Side sliding window leak

Has anyone removed there sliding windows before one of my seems to be weeping internally from what seems to be a join in the center on the bottom of seal i would like to replace the seals on all of the window when i get round to doing a respray but its very confusing when looking on mega zip as to what parts are needed to do this as the seal/sliding channels seems to be all one part but shows as multiple on parts diagrams any help and advise would be much appreciated