when i did mine i smacked the bottom against a steel /iron anval . the body wont pop out of the housing either , if you notice the body sits into the housing about an 1/8 " when you smack it it should become flush with the housing and then you grab it with pliers/ vice grips or something and pull it out .
Remember: you are smacking the whole lifter down to pop the body out , not setting the lifter on somthing and then smacking it with an object . hope this helps .