To remove the Valve Spring Retainers (VSR), I rented a Valve Spring Compressor Tool from Advance Auto Parts. I actually had to purchase it for $50 and then I will get a FULL refund if returned within 45 Days. However the compressor won't fit into the pocket areas to remove the retainers. So, I made a Stainless Steel Extension Adaptor (and a Nylon one) witch worked very well.