1. When joining the new and existing parts, temporarily install and fit the new part in position, measure each dimension according to the body dimension, then adjust the position to align it to the standard dimensions.
2. Drill holes for plug welds before installing new parts.
3. Weld in 5 locations indicated by (A), then trial-fit the inner and reinforcement.
4. Weld in 10 locations indicated by (B), then install the inner and reinforcement to the existing parts.
5. After trial-fitting new parts, make sure the related parts fit properly.
