The trick when you put new sealant in, is not to put it on too thick. Cut the caulk tube nozzle pretty small, and if it is not a skill you know, practice on a box first. You want a fairly thin bead, even as can be. When you get to the corner, you do tend to get more as you turn, but you will smooth it out with a finger when you have it all on. Any excess can be wiped off, and you smush it down so at the edge that touches the glass it is down to nothing in thickness.. the taped edge. Corners I usually have to wipe some out, it is hard to get it really neat unless you do a lot of it and get practiced at it.
You'll need a caulking gun.. very cheap at hardware or paint dept's.
If you tape, remove it before the silicone begins to skin over, which can start in less than a half hour. Once skinned, it will take a lot of the wet stuff with it when you pull the tape and you will likely have to do it all over again, which is a terrible thing to have to do. So yank tape it as soon as you finish smoothing out. If it smears, no worry, you can scrape if off when dry. Not as hard as scraping out the thick stuff at all.
Ideally, you get a neat line about a quarter inch wide on each side of the angles where the panes meet. Up to a half inch is fine, but won't look as tidy.