First align part for equal edge distance on ends, clamp everything so you can get at the holes and transfer punch the centers for all the holes.
Used 1/16", 3/32", #30, #21, 11/64" to progressively enlarge the holes, then ream to 3/16 using exsisting holes as a guide. Deburr, then align the part back on the spar and bolt together with all the AN-3's.
Clamp the root end away from the holes, use reamer and cutting oil and back drill the holes turning the reamer backwards till it touches the undersized hole in the new part. Stop and switch drill motor to forward and ream through. Once it breaks through either continue through or stop and reverse drill motor to back it out.