Deb is right about the attorney. Every state has different laws concerning condos. Before you do anything, or initiate a fight with the condo board, be sure you are on solid legal ground. Reading the docs and having an attorney look them over needs to be your first steps.
While I hate to disagree with anyone here, I must say Do Not Change the Locks before you have checked that you have the right to do so. I know, in condos in my state, most require that the board have a key to your unit. However, they are also prohibited from entering except in case of emergency. You will probably find it spelled out in the condo docs.