Although the vacuum pump will work, you can bleed them for free and save yourself a trip to town. Take the lid off of the master cylinder and keep the fluid level full. Then crack the bleeder valves on the calipers and let the fluid run out of them for a while. (I catch the fluid with a cup and reuse because I'm a tightass) Make sure that your bleeder valves are working and not plugged up. Take them off and see if you can blow through them. Just let the fluid run through the system for awhile and shut the valves off, put the lid on and you'll be set. I just did the yfz450 brake swap last night and it took me 10min to bleed the system, just as described!