Re: Can I change the bridge pickup...
Watch for an out of phase condition, in which the two pickups together will sound weak. A Lil '59 doesn't have a metal baseplate, right? If so you should have enough flexibility in how you can connect it, to correct the out of phase condition.
Your stock Fender neck pickup has one of its' two leads connected to the pickup cover so if you do a simple reverse of them (instead of the '59) you'll have the cover hot and it will be noisy; you could rewire that cover connection to the other lead, or better yet, to an independent third wire, to correct that. But that requires a bit of work and you have to be very careful doing that so you don't damage the pickup in the process.
So if the '59 has no baseplate, the simple way to wire them in phase is to connect the '59 smartly.