The wheel arches should be pretty well trimmed to size with little if any further trimming needed. only around the splitter may be an issue depending where your splitter ended up after the splitter mods, if this was done at all?
Fronts first.
The front of the rocker is trimmed to allow the arch to fit as trimmed.
A bracket needs to be made to mount the bottom edge.
The splitter gets a bracket for mounting also, both are about an inch back from the edge.
The fender returns need to be reduced to allow the arch to be fitted, and to clear the tire. just a nice blend between the three points will be fine.
Rear of front
Top of front
Front of front
Note the arch dose not come all the way out to the edge of the fender.
This is roughly where it will sit at the top.
And the front and rear installed images.
Only the two 5mm bolts are required to hold the arch.
Fronts first.
The front of the rocker is trimmed to allow the arch to fit as trimmed.
A bracket needs to be made to mount the bottom edge.
The splitter gets a bracket for mounting also, both are about an inch back from the edge.
The fender returns need to be reduced to allow the arch to be fitted, and to clear the tire. just a nice blend between the three points will be fine.
Rear of front
Top of front
Front of front
Note the arch dose not come all the way out to the edge of the fender.
This is roughly where it will sit at the top.
And the front and rear installed images.
Only the two 5mm bolts are required to hold the arch.