I plan on divorcing my husband and I want his name taken off the deed to the condo that my sister bought for all 3 of us, she is disabled and unable to live on her own. We all signed a right to ownership paper but now with a divorce in near future I want him to sign off, he has no objections, I just don't know who to contact to get this done.. can anyone point me in the right direction to get this started.. thanks.

Simple answer: see an attorney to prepare a deed.

You might wish to wait until you have started the divorce process and have it turned over by the courts so it doesn't somehow backfire on you. Just make it a part of the marital settlement and your attorney should be able to handle the rest.