You can do it buy pumping the lever, but the risk you run doing it that way is damaging the piston seal in the master cylinder. Because once you go past the furthest point that it is used to going, there could be some particles/pits that have formed in the master cylinder wall. Essentially it would cut the seal causing the pressure that you are trying to create to get around the piston. Unless you honed it out and have just rebuilt it. If you do not have the tool, I think you can get a loaner from your local auto parts store. I have gotten a borrowed a tap and die set when I did my chrome wheels. Hope this helps you out. Good luck with the install.
I reverse bleed them. By taking a vynil hose that fits the bleeder valve
and holding it higher than the mastercylinder. Open the bleeder and the air will go up and out thru the top at the mastercylinder. Dont walk off and leave it or it can over flow. Speed bleeders are a different way they are put inplace of the bleeder valve and only let fluid bleed out with no air going back in when pumping the mc.