First, you'll have to remove the little brass nut, positive contact, brass washers, and white delrin insulator....
Then, you have to remove the big brass nut, on the underside of the 510...
I use a small pair of channel lock pliers to grab the nut...
Once the nut is off, you'll then have to remove the 510 housing from the cap.
This might be tricky, as it is
threaded into the cap, cranked down tight, and there's no good way to get a hold of it, without a 510 installation tool.....
I use one of these to install 'em.....
A tool like this could be used from the underside of the cap, to drive the housing up from the bottom... An old carto could be probably be used for this, as well... You could just thread the carto in from the underside, grab the carto with some pliers, and turn it clockwise to get it started...
Some will come out easily, some not so much.... If you wanted to see if you'll be able to do it yourself, I would try to remove and reinstall your existing 510. If you can do that, and get it good and tight so that everything works properly, then you should be able to do the job.