is there a way to replace the lower balljoint while the knuckle is still in the car?? is there a tool i can use please let me know . wanna know if it can be done with the upper part of the knuckle still bolted ?

 

No.

 

Pound it out with a BFH. I have done it before, but you may have to soak it in penetrating oil first.

 

There's not a lot of space down there with the axle in the way. You can probably get it out but putting a new one in will be a pain in the ***. I had my knuckles out and I had to torch them to get the LBJ to drop in. I had to beat the LBJ out with a hammer - not BFH - but I did saw off the threaded portion first to give me a better surface area to whack.

Good luck.