This is an advanced conversion and it does require some patience.
First I cut off the parts I do not need on the six limbs. (The reddish marked areas).
I took the tank tracks and glued the 2 & 1 piece together. I also glued a strip of plasticard under the bottom to "thicken" up the body and give it more strength. This is the body of the Defiler.
Then out of plastic card I created four "foot blades" similar to what is on the 40K Defiler. I cut off the small "pins" on the tank track. I then glued the four legs into the indentions on the tank track. You may have to trim the tank track indentions so the legs fit. (click on the image for a larger picture).
I cut off the tip of the Orlock lasgun to use as my battle cannon. (the reddish marked area).
I cut off the two lascannon barrels from the right Land Raider sponson. Then cut off the single lascannon on the Predator sponson and glue the two barrels onto the Predator sponson. Now you have a Reaper Autocannon. (The reddish marked area).
In hindsight I think it would have been better to order both the left and right Predator flamer sponsons and replace the right flamer with the two barrels. That way the Reaper Autocannon would be turned slightly out. But that is a minor cosmetic look.
Taking the Epic Predator Turret, I cut the skulls off the sides of the Turret. I cut off the autocannon barrel and replaced it with the battle cannon.Then I glued the Sponsons to the side of the Turret. This is the turret of the Defiler.
Next I glued on the "foot blades" to the legs and the chaos ram bar to the main body. It is starting to look like a Defiler. (click on the image for a larger picture).
I put aside the main body and turret to work on the claw arms. This ended being the most difficult part (imho). I traced the pattern of the claw from a picture of the 40k Defiler sprue. I glued the template to a piece of plasticard and cut out the shape with a jewelers saw. I cut out 4 claw pieces (2 for each claw). Here is the Template.
I glued two claw pieces together with the "thumb" piece in between and a bit of plastic to separate the two claw pieces. I trimed down the length of the claws a bit and cut a "C" shape in the end, then I glued it to the arm piece. (click on the image for a larger picture).
I cut some armour plating out of a plastic blister packaging for the claws and glued it on to each claw. Then I glued the claw arms to the main body. I also added the first turret spacer ring (an epic infantry base). (click on the image for a larger picture).
I added a second smaller turret spacer ring and then glued the turret on. I glued a skull (cut off from the side of the predator turret) on top of the Turret hatch. I do not like the Defiler "head on a machine" look. So you are on your own if you want to do that. I cut down the BFG Chaos tower and glued it to the back to look like a set of exhaust pipes. That is it. Finished!!! (click on the image for a larger picture).