OK. This is very easy to do. Get a lvl 8 mage and take him to this part of IF:
http://img276.imageshack.us/img276/6496/oldif1ml5.png
Now go to that circled corner and both start jumping up it. Go right to the roof and start a duel. Jump down and go to this place:
Stand with your back to it like this:
http://img267.imageshack.us/img267/6288/oldif3cf8.png
Then keep walking backwards agaisnt the wall. Whilst you're doing that get the mage to sheep you. It make take a few trys but you will eventually unmorph on the other side.....VOILA! OLD IF!
Enjoy
(cant be bothered with pictures of it inside....look for yourself)
(also....if the mage wants to get in too you should sheep in enough people, including a lock, to summon him.....or get another mage who doesnt care)