Hey, yeap, 5's pro is explained on beyond, but it's a really simple, yet effective, idea:
First week: 65%x5, 75%x5, 85%x5
Second Week: 70%x5, 80%x5, 90%x5
Third week: 75%x5, 85%x5, 95%x5
On the fourth week update your TM by 10 and 5 pounds and continue, 6 week is deload (this is another difference in beyond).
As assistance, in case you don't know what FSL is, here's the trick:
Do your normal work as stated above and after that do this:
First week: 3-5 sets 5-8 reps with 65%
Second week: 3-5 sets 5-8 reps with 70%
Third week: 3-5 sets 5-8 reps with 75%
I guess by now you know why it's called First Set Last. On my book 4x8 is the way to go. Perhaps I could recommend you 5x8 on the upper movements and 5x5 on the lower but in the end is completely up to you. Any more assistance should be very low, some rows, dips, back raises, etc.
I also don't know what is your training frequency (2,3 or 4 days) so you might need to cut back some assitance.