Drain the tank and remove the petc0ck by yanking the 2 bolts that hold it to the tank.  On my bike, I could do this with the tank on, but you might have to remove your tank to do it (see tank removal thread:  http://suzukisavage.com/cgi-bin/YaBB.pl?board=tech;action=display;num=1100708616).  

Here's what you'll have on your bench:


We are going to seal off the hole that corresponds to "PRI", making it "OFF" for fuel flow.  Then we will delete the vac diaghragm so fuel will actually flow in "ON" and "RES".

The plastic fuel inlet tube is very fragile so be careful.  Once you get it off, you'll see how the tubes are different lengths and the sockets in the petc0ck are correspondingly different depths, so it will only go back and fully seat one way:





CAREFUL, there's a little coil spring  on the backside of the lever that will induce Turrets syndrome if lost.



The little white truncated cone shaped plastic valve is what we are going to bastardize modify.  It has two holes on opposing sides, one bigger and one smaller:



I made a plug so I could screw it in with epoxy.  You might have a better idea:



Grind or sand the plug off flush or just below flush.  If you use a Dremel like I did, GO SLOW and grind in short bursts followed by plenty cool down.  If you get it too hot, the plug will move and you'll have to start over and re-fit the plug.  
Once that's done, you have sealed off the "PRI" hole, making it "OFF".  Set it aside for now and we'll open up the back to defeat the nasty vacuum diaphragm (next post).

With the "PRI" hole plugged in the white plastic valve, we now line up the plastic valve so the remaining  bigger hole lines up with the fuel inlets.  In these pics, I turned the selector lever to match the plastic valve position. and finally installed the lever by the third photo.  I used nails and red lines to show where the hole lines up, as I could not photo it adequately.  You, however, can see how the hole lines up by looking down the top of the petc0ck with good lighting.  You don't need no stinking nails.







At this point you can admire your handywork as the plug is visible from the top of the petc0ck when the lever is in "PRI" oops now it's "OFF".  Better make a label for that...  Put the back cover & gasket on, RTV sealer optional, cap the vacuum port, and re-install the fuel inlet tube recalling how the tubes have different lengths to match the depths of the inlets on the petc0ck.  DO NOT PUSH ON THE TOP OF THE PLASTIC INLET TUBE - YOU WILL BEND OR BREAK IT!  Push on the base only, and use that little screwdriver your pried it off with:



[glow=red,2,300]BE SURE TO CAP OFF THE VACUUM PORT ON THE CARBURETOR THAT USED TO RUN THE PETC0CK! [/glow]

You are now DONE and ready to put your manual work inducing misery whip back on the bike, fill the tank, and watch for leaks.

You may get a leak around the lever, since we disturbed that O-ring.  If you do, replace the O-ring.  Go to the hardware store and get a #4 O-ring out of the fauct parts section (around plumbing and the new faucets).  At least here in Arlington at Lowe's it was marked as a #4, but take the old one with you to make sure.  Things get messed up in those big stores and most of the employees are too overworked to care about fixing it.  The #4 is a perfect fit and stopped my leak.



RTV Silicone can help seal the petc0ck body to the tank if need be, further enraging the pretty boys who called you a hack for doing this conversion.  

Let me know if you have any further questions.[glow=red,2,300] [/glow]

Just did the conversion on the "Leaky Petcock" I got from Verslagen.  

Notes:  I used a nylon 10-24 screw I bought from the hardware store.  Much cheaper, 24 cents (US).   And , it is much much much easier to work with too.  I suggest using a tap to make the threads in the smaller PRI hole in the valve body.  I just pushed in a metal 10-24 bolt to make the threads and had a slight bump form  that I had to file down.  I used some Permetex Ultra Copper to do the seal. (I had it from the head plug change) See pict.

Second,  I made an aluminum plate on the back for thinner profile.  No chance for the old port to leak and there is no mistaking it's been converted.

Third,  I have a letter punch set I got from Harbor Freight, (1/8 " letters).  I lightly filed the PRI and punched OFF in it's place.  I am not happy with results. I used a slightly camphered piece of metal backing to punch the letters so the center F shifted.  

Click picture for larger image.