You will need to seperate the elbows from the clamps. They are likely to stick like the proverbial. The best way I found was to insert the clamp bolt fairly fully then use Gas pliers or similar to compress the end of the bolt to the frame. The elbow will pop out. Coppergrease before re-fitting.
Those elbows are a taper fit inside the piston holder, as described the best way to loosen them is with a 13mm spanner, later versions had the interlocking teeth, which in my honest opinion never allowed a perfect setup. The later again Evo II mounting system is fantastic and easier to setup.