Please take some time to install the cowl and work carefully.
The nuts are already glued on the fuselage- holders for the cowl.
The wood frame inside the cowl gives you the right position
You only have to transfer to the holes to the cowl. This is most easily with tape.....
For the cutouts of the motor / muffler sections at the cowl we advise you first, like to see at the picture, to scale
the cutouts on paper. Then postpone cowl and fix it and you can transfer the cutouts...
The engine cowl