Handlebar bar end

Well this has got me well stumped.
Want to replace the aged foam grips on my newly acquired V35. It has steel bar ends fitted and they appear to have an M4 hex key recessed in the middle - which seems logical.
Except that the M4 hex key refuses (and I mean refuses) to budge. I obviously don’t want to round the key off but I’ve put a lot of pressure on it and no movement. Same for the other side as well.
It occurred maybe they are loctited (why??) so maybe heat would help but as the switchgear is up the road I am a bit reluctant.
Anyone else had this problem?
Any suggestions received gratefully…

It could just be rusted on. In some cases the bolt draws a tapered cylindrical wedge towards the end of the bar forcing a sleeve out to grip on the inside of the handlebar. Most of these internal parts can corrode as they can be cast aluminium (wedge) or plain uncoated steel (sleeve) zinc plated steel (bolt). All of these different materials in an environment where moisture from condensation can be present will be a recipe for corrosion. Apply copious amounts of penetration oil to any holes in the bars (some have cables within them) sods law says your only holes are at the ends where the end caps are stuck!

Worst case situation, if the above doesn’t work. remove the handlebar switches and cut the grips off grip the bar ends firmly with mole grips (other animals are available) and apply heat and loads of welly.

Good luck!

Some heat applied to the bar end shouldn’t travel up the bars too much, certainly not enough to damage the switchgear. You can keep an eye on it by feel.
Heat is pretty amazing at releasing stuck parts.

If all else fails then a 1/8th hole drilled into the handlebar under the grip but at least 2" in (so as not to drill into the bar end fixing) will allow you to insert the WD40 straw to squirt into the centre of the bars. Also some bars already have holes in them to allow for the spigots on the twist grip or switch gear to stop them revolving. If you do have to drill then a sharp crack with a centre pop will often penetrate the hard chrome outer leaving your drill a much easier path. If possible have the bar ends sloping down to allow the WD40 to sit in a puddle around the fixing.