I had a friend like that too... I would lose to him every week. But, I just followed good ol' Dan Harrington's advice which is essentially, you make the most money playing the "opposite" of what people think you play.
I had generally had a weak-tight image. This wasn't because I actually was weak-tight, but it was because I had gotten burned by so many of my friends playing loose and beating me with Q5o making two pair on the river that I became tentative when they would bet out.. I had no clue what they had and so my TPTK or my low set with flush/straight draws didn't look so good to me anymore.

So a couple of times (not many) I would raise with something like 56s/89s just knowing that he was going to call with his trash. If I didn't the flop, then I folded. Once I hit the flop and took his money with a 4-8 straight and another I hit the flop with a 6-high straight. Granted there were a number of times that I raised and then folded. But eventually showing down some hands where I raised with less than premium holdings helped my image changed from weak-tight to a little unpredictable(Borderline LPP, if they knew what that was.) People saw that I wasn't only raising with high cards and limping with medium holdings.

He began to learn that when I raised and low cards were on the board, he wasn't going to be able to take my money as easily.