Anyone know how to take the seat lock off the side rail?

[Toner]

Been cleaning the back end of my bike today and figured I'd do something about those rusty side rails.
The right one came off easy but the left one has the seat lock block attached to it.
The lock part looks like it should pop out some how but I can't fire out how to get any slack on the cable. 
Anyone ever do it?

[user11235813]

pop the yellow bit out at the bike end, then you can get the slack you need at the other end to pop that out.

[tobyd]

I think the whole lock assembly undoes with 2 screws?

[Toner]

pop the yellow bit out at the bike end, then you can get the slack you need at the other end to pop that out.

Cheers, got it out finally. The lock end is tricky even with the slack