In that case, definitely rack to a bucket. Freeze/thaw the fruit first, then rack the beer on top of it. You might need to add some fresh yeast, depending on how long it's already been in secondary. So after some time on the fruit in tertiary, you can rack to quaternary to help it clear.
How much fruit to add depends on the base beer and how strong of a fruit presence you want, so if you gave us some style/strength details we can better suggest lbs/gallon.
<edited to add last bits>