If anyone would like to know how to remove armor in Assassin's Creed 2, you just need to use the glitch that is used in Assassin's Creed Revelations to get weapons early, but on the Armor sets in AC2. But you must have an armor stand that only has the greaves on it. In my case, I used the missaglais armor set. I selected the greaves, then changed to the vambrace at the last second and the entire second hidden blade vanished but Ezio could still use it. Also I used that on the spaulders and they disappeared aswell.
No problem, but I have to warn you that, as far as I know it only works on the pieces of armor you have selected up until you reach the sequence that enables you to buy the armor and then it automatically equips it. But have fun anyway.