I found this on another board and built it myself and it was the best DIY tool I have made and used in a long time. It made the job so easy and I had it out in less than 2 minutes on my 05 Legacy (after soaking it for a night with fluid).
http://www.clubwrx.net/forums/suspension-handling/134369210-diy-subaru-ball-joint-removal-tool-around-18-1-lug-nut.html(source)
I went to LOWES as well for all of this stuff as 1-1/2 inch stuff was not at many places like Can Tire, Home Depot or RONA.
1@1-1/2x4 pipe nipple
1@1-1/2 pipe coupling
1@1-1/2 galv pipe cap
1@1/2-13 all thread 1' lg (cut to 8")
1@12x1.25mm Subaru lug nut
1@1/2-13 nut
2@1/2" washer
So step 1 is to weld the lug nut to the end of the all thread. If you don't have a welder, find a buddy and buy him a beer.
The parts:
Step 2:
Assemble the pipe coupling and nipple and tighten.
Step 3:
Drill a 1/2" hole in the center of the cap for the all thread to pass through.
Step 4:
Screw cap onto nipple.
Step 5:
Trim the all thread to 8" with a hack saw or sawzall.
Step 6:
Grind flats for crescent wrench on ends of all thread.
Step 7:
Test assemble everything.
Step 8:
Use the damn thing.
First thread the lug nut onto the ball joint stud.
Then slip the housing over and install the washers and nut.
Then tighten like this:
Use a crescent wrench and 3/4" wrench.
Ball joint will pop right out.
