Could anyone give me a walkthrough for the Revolution level What a fantastic pair of birds? im completely stuck.

Make the first lemming (L1) walk a little ways, then mine.  The next lemming (L2) will turn around.  Make him mine near the switch.  The lemming following him (L3) should mine left under the entrance.  Two of the miners (L1 and L3) should hit steel, trapping the crowd, while the other miner (L2) will break through on the left.  Make him build over the gap, and bash through the thin wall.  Let him walk a ways, then mine.  Shortly before he breaks through the bottom of the wall, make him bash.  Make him dig to reach the exit once he is safely past the bird.  Release the crowd by building over the hole that L3 mined.

If you run out of time, release the crowd a little before the leader is finished.

Feel free to ask for help on another level if you need it.  Also, you can try going to this site.  
http://www.deinonych.com/lemmings/lemmrev_walk.shtml

Thanks! ;)