Okay. MW minis don't need much different equipment to paint than BT minis, but they are bigger.
First thing you need is warm, soapy water. Always a good idea to wash, then rinse the minis, and let them dry. Removes any stuff that might stop the paint from sticking.
Then you need to decide if you want to keep using the click-dial. if so, then remove the mini from the base. A thin screwdriver can help here, as can putting the minis in the freezer for an hour or so (the glue goes brittle). if not, then dont' worry, but the dial will get covered in paint at some point.
Then you need a primer. This is something to cover the existing paintjob. I don't recommend bothering stripping the existing paintscheme, as it's pretty thin anyway. You can use white, grey or black primer as you choose - the main point is to cover up the original mini so you get a consistent colour later on. You can use any brush-on or spray paint. I'd recommend acrylic paints for brush-on - the brushes clean in water, and the paint dries quicker. I use a cheap spraycan of automotive primer often myself.
Then paints. Again, unless you're into airbrushing with the equipment and all, stick to acrylic (water-based) paints. You can get them from hobby stores catering to the RC and plastic kit folks, or you can buy them from art supply shops. Many acrylic paints can be a little thick, but you can just thin them with warer. You want a consistency just under tomato sauce ;) - enough to leave a good colour on after the brushstrike, without clogging the mini up.
Brushes - get a larger flat brush (say 3/8"), a smaller flat brush (say 1/8") and a very small round brush (size 0 or 00). The larger brush is for doing the base coat (see below), the thinner for adding details, and the thinnest for the fiddly bits and fixing painting errors.
Work in a good well-lit area. it helps to be not too dusty or sandy (which will stick to wet paint).
Firgure out what you want to do. Say you want to repaint a Banson's Mjolnir into Republic colours. The Republic use a darg green base with maroon details, plus black & metallic bits. Once your prime is dry, paint the whole mini with the dark green using the bigger brush. When that's dry, colour the shoulders, knees etc with the medium brush. Try and keep the red paint where you want it to go; don't overload the brush. Then paint in the joints, gunbarrels etc with metallic paint, using whichever smaller brush works better. Then go back with the red and green to fix any "bleeds" where one colour goes where it shouldn't.
That's a really basic outline. DO that a few times, and your confidence & accuracy will increase. Then we can talk about some further techniques - drybrushing, washes, highlighting - to take you further down the rabbithole into painting :)
Welcome to the forums, and make sure to post pics! And the best way to get better is to do, to practice, and to try new things.
Cheers!
W.
