Review of Cap Removal Tool:

These work fantastic for LDPE bottles (soft plastic). I place the wedge right under the nozzle lid and gently maneuver it off. It works alright for PET too (hard plastic). I think for those a pair of pliers is easier but I no longer use the hard plastic much as the other kind is much easier to squeeze, refill, and doesn't seem to wear out -- highly recommend both for DIYers.