I have a high level char and want to run episodes and missions with a low level char but it seems like everything is too easy for me and more importantly too hard for my friend, is there anyway to turn down XP so that both of use can have a more 'even' experience?

Have your friend be the team leader and match his level.

Also, if you want to match his level more closely and make it even more challenging, in addition to using the Mentor feature that DVSaris recommended, you can also:

1) Use tier appropriate gear (If your VA is playing with a Lt.Cmdr, for example, you switch out all your Mk X-XII gear for Mk III or IV gear).
2) For space combat use one of your older, lower-tiered ships. You'll then have the level appropriate number of BO powers, weapon slots, etc to match your fiend.
3) If away teams are involved, use only his BOs.

Have fun!