Hi ive had same problem in the past and found there are two ways to bleed the brakes 1/ use a brake bleed syringe (ebay about £5.00) Take top off of master cylinder crack open bleed nipple push syringe on to bleed nipple and draw out all the fluid . then fill syringe with fluid and gently squeeze in fluid keeping eye on master cylinder level 2/ remove calliper hold it above resevoire and put something between the pads (thicker than the disc ie tyre lever.Either ways work !!!