They will take Led. you just need to swap the holder for a GU10.

Not expensive at all.

In fact my brother in law is an electrictian and hes just sources some new LED lights which are the same size as the normal GU10 halogens and have a much better light spread than the older LED's from the past few years.

Its defo possible tho mate.

Ill whiz a lamp apart tommrow and take some pics for you so you can see the internals.