There are many procedures of mole removal like by shave or deep elliptical excision, excision with cauterization (a tool is used to burn away the mole) and laser removal. Your dermatologist may choose excision with or without stitches, depending on the depth of the mole and the type of cosmetic outcome desired.
However there is no method as such to prevent the moles from growing.
I hope it helps. Take care and regards.