if its anything like the TM, which it should be:
remove slide,
remove front slide rail and triger spring,
pull hammer assembly out a little, enough to unhook the trigger bar that runs from trigger to hammer by rotating the hammer forward towards the muzzle ( be carefull of the small spring and loose bit of the hammer)
and then it should all just pull out with the trigger bar attached to the trigger, the safety may need presing so it fits.
The trigger bar can then be removed. its just a small pin.
i seem to remember a you tube vid called La Zouch? [edit]
https://www.youtube.com/playlist?list=PLgX2Vln1T55u-45t4yFGwd14dxp1gBB4K