Redford;
Done lots of those over the years!! Leading edge. Cut the LE spar at a 45 degree angle, preferably halfway between 2 ribs. cut new piece at 45 and join together. glue a strip across the backside between the ribs, maybe 3/8 thick hard balsa. Sheeting. Cut 45 degree between ribs. glue a 1 in wide strip of balsa with the grain going crossways under the rib with 1/2 in sticking out. Splice the outer sheeting on top of that. Do the same with spars.