I do it without a vice, and it works fine.
Second axis (sight bubble) is just a matter of getting the bow vertical and having your bubble verify that. I hold a 4' level to the bow at the ends of the riser and see what the sight bubble reads when the riser is perfectly vertical. Adjust a little if needed and check again until perfect...2nd axis adjustment is done. If you don't have a level, then a wall or door frame can be used, but walls and doors are rarely perfect: a level is better.
Third axis is a matter of a sight hitting right or left on steep shots due to the pins/frame needing to be pivoted toward the archer or away like a gate. Third axis is adjusted by shooting it in. Shops can get it close most of the time, but to get it right for you and your draw, then you'll still want to shoot it in, even after taking it to the shop. Shoot lots of very steep up and downhill shots, making sure you're watching your 2nd axis bubble on your sight frame. If you don't have a hill steep enough (most don't), then put your target 15' from your house and shoot off the peak of the roof or match that with a treestand. Your 3rd axis needs adjusted only if your shots are off left or right, then adjust appropriately a tiny amount and try again until you don't hit right or left on either up or downhill shots. 3rd axis adjustment is done. The vast majority of us don't need 3rd axis adjustments, but it sells well, so this is how to do it.
Most important step now: put a dot of white-out on each pivot point, so you'll know if you've bumped it or if it changed somehow. As long as you have it out, do the same for the rest and any other places you will want to know didn't move. You'll feel good about it in the field when you see none of the dots are cracked or misaligned.
