Besides the obvious studying new scales, what would be some of your first steps if you were attempting to convert to Jazz?
Forget everything you know... well not really, but rethink it...
Where I - IV - V is a basis in rock and popular music, IIm7 - V7 - IMaj7 tends to be a starting point in jazz.
Like someone said, listen to a lot of jazz. You most likely played rock and metal because you liked it... you need to like jazz, not saying that you don't, but soaking it up is important.
Find YouTube videos, instruction, but in the beginning look for stuff like "Jazz For Rockers" or something along those lines.
They'll most likely present it in a more familiar way. Many unintentionally will talk over one's head using unfamiliar terminology and concepts. You definitely need to learn such lingo, but it can seem overwhelming and you want to get your feet wet, get a good feel for it without it seeming too frustrating.
Learn standards, watch some tutorial videos of these.
Have fun with it!