my buddy just tried to remove his head cover to re-torque the nuts on his  2015 with 4000 on it  and he cant get it  off.because there is not enuf room.frame to motor .do we have to remove the motor to re-torque the cyl nuts. anyone having this problem.dont want to go b\deep .into my bike and have same problem.because that would really.will enuf said on that. thanks

I believe torquing the head bolts is like maintenance just like checking the valve lash.
You can get the valve cover off with the motor still in frame but it's tight.
Most bikes with head plug leaks are due to the mechanic not sealing the 1 head plug cover correctly, make sure to seal yours correctly

There really is no need to ,haven't touched mine in 24 years , yes the Book says to but it's there so you'll take it to the dealership , they might check your compression and if it's with in spec won't do it either ,but probably charge you for it. those bolts are only torqued to 21-24 lbs  treat it as one of those things that" if it's not broke don't fix it" .  
  sooner or later you'll have the headplug leak ,and oil will run across the front fins right on level with the head and cylinder newbies mistake this is a head gasket leak,it's not, but you will have to replace the plug and put sealent around it ,something the factory never has done
if your buddy can't get the cap off is it because the long center bolt doesn't have enough room to come out?. just remove the cap with the bolt in it, and you'll have to insert it in the cap again as you reinstall it. Some frames welded at the factory come out larger or smaller , if he can't get the cap off , he can pull thr lower motor casing bolts ( the ones that hold the front pegs ) that will allow the motor to swing down between the lower frame rails giving him the extra room he needs.

I think if you only go around twice and the torque is in spec , that's the best you're going to do without stretching the bolts ,replacement might be overkill, unless the bolts bolt bottom out inside the cap nut and you can't reach the targeted torque their probably OK to reuse. I'd just be sure to replace the copper sealing washers you use under the nuts,if their not beat you could anneal them and use them over again as well

You can't just "re-torque" the head by putting a torque wrench on and pulling on the handle.  The nuts corrode a bit and take a "set", and it takes a lot of muscle to get them to break loose.

To properly torque the nuts to need to remove them and clean up the threads, and apply new anti-sieze or sealer to the threads and nuts.  Doing so is also a place for a potential new oil leak.  Drag Bike Mike did a thread on the proper way to get the nuts sealed.

I really would just leave the nuts alone and not bother trying to retorque them.

I too am in the camp of if there's no compression leak, leave the head bolts alone. And if there is a compression leak, it's probably not because of loose head bolts, it's usually a blown gasket.

What is it that your buddy is trying to correct 1Sulg? If compression seems to be low, a leak-down test is in order, not tightening bolts. You're more likely to snap a torqued head bolt than to move it to a tighter position.

When stuffs working
And you decide to fix it
The best you can hope for is
Stuff still works..
I bought one new
Sold it with twenty thousand miles on it
Never touched head bolts

thanks all .