Place wing joiners and glue them into wing with some ca
Cut the top sheeting , mark it with some lines from the inner panel as lead .
And glue top sheeting assembly with thick ca or use slow white glue .
Take of panel, Sand all edges and place leading edge from 6x20 balsa , sand to shape as per plan
Join tip blocks and place to wing at R8 sand tips with course paper and razorplane ,
Take out opening for your retracts, use some scrap ply to fill the mount till the top of the retract unit is
flush with the wing sheeting