Training for 500 pound lift with 408 Pounds

Lifts lifts and lifts, put the work in now and then relax a few days then try 500 with a single lift, shouldn't be to far away, hopefully i can do a good lift, i will be wearing some cloths that are a little more thin and slippery when i do the lift, i don't know if i will be able to do it in the cloths, the cable was getting stuck on my back, making it harder.