Trouble with entities

[supertanker]

I'm having some trouble with entities and GTKRADIANT

First, how do I make an object (Say, a func_plat) turn back into a normal brush?

Second, how can I 'join' entities? like say I have two lift entities, is it posible to join them into one?

[jitspoe]

I'm not sure how you do it in radiant, but in BSP, there's a "revert to world" option.  To join them, I'd say you have to revert them both back to the world, select all the brushes at once, then make it a single plat entity.