however heating up a record and bending back into shape using various methods will work... it does so by changing the shape of ur record and then hardening when it cools down.
there is no guarantee you will not change the shape of the groves on the record and as a result it will alter the sound.
just live with it, if it still plays its fine.
I've got a fair few that ride the platter like a ferry crossing the english channel, looks weird but give a shit
Put it on top of something flat, like a big, hardback book, then pile lots of other heavy books on top of it (phonebooks and the like). Leave it somewhere nice and warm, like on a windowsill that gets lots of sunlight, for about a week. Though it won't flatten it out completely, it should make it much better.