Door speaker wiring question

[lec6213]

Im installing new speakers and assume that I need to run a new line set to the door from my trunk mounted crossovers. There is no way to use the existing lines in place is there? I assume there is stock crossover already in place? And provided I cannot use the existing lines, how do I run the new lines sets!

I have tried to fish thru the body-door conduit and to no luck. I hope there is a easy way to do this, but I'm doubtful.

Also the new feed is 150 rms to each door, if the stock lines can be used, with regards to wire guage, do i need torun new lines anyways.

Thanks