I am working with an assembly that was created by someone else. I have designed a new part that will replace an existing part. In removing the old part I removed all the mates from the model tree but when I go to delete it from the assembly it still has a whole list assembly constraints. If I just accept to delete the part with the assembly constraints 90% of my assembly goes with it. Why can I not delete this part? What other types of constraints could be affecting me?