[JoeRockEHF]

One easy way is to double click on them to open them in Paint. Then click on File and go to Save As and down on the bottom of the box that pops up with where you want to save it and what name you can choose what extension to save it as. Click on the bmp and there you go.

There's a program that lets you do all of them at once but I've never used it and am not familiar with it. You'll have to go one by one otherwise. Hope this helps.