A few threads that already touched on this directly -
Yes, both mention use of the NATO provided materials, but also include usage of former and current Russian/Soviet block equipment.
Short version, small arms, easy. Military equipment that is non-weaponized (various trucks/transport/etc), also pretty easy. Specialized gear (weaponized or not) - as discussed upthread here, requires matching it with people who have the skills, so much more difficult.
Hopefully the links will help prevent too much re-inventing the wheel.
