its pretty hard without them,.. i tried using some skinny flat head screwdrivers... work beatifully the 1st time,. not so good the second time.. kinda bent some ****.. so i wouldnt recommend it without the pullers.
Like others stated, a set of small screw drivers or a metal coat hanger and maybe you'll get lucky. Or break down and buy the tool for $5 in the Wal-Mart car stereo section and maybe take it back when your done with it
Whatever you try, the goal is to stick whatever in the holes and push them in the outward direction, this will pull the latch in and release the clips.