Sure, it can be done. I installed that head unit in my 08 not long ago. This sticky thread is a great place to start:
I prefer Sonic Electronix
, but this same stuff can be bought at Crutchfield:
Since you have JBL
system, you will need this harness:
Get this to retain steering wheel controls (no programming involved):
This is not necessary, but makes simple work of wiring the above steering wheel interface. It has been out of stock everywhere lately, but you can find it on eBay
You can buy an add-on GPS unit for the avhp4300dvd:
There are two dash kits that will work. People seem to be divided on which is best. I think they are both merely adequate, but favor the Schosche kit because it seems to fit better:
Metra also makes a kit that is textured like the stock dash piece:
Grab one of these if you plan to use an iPhone or iPod:
Grab one of these relays for your bypass:
And finally, look here for instructions on how to wire the bypass relay:
Unless you plan to solder, you will also need some crimp connectors and a crimper. Overall, it is pretty straightforward to install an aftermarket head unit.
When I installed this head unit, I spent quite a bit of time fussing with the placement. In the end, I'm very happy with the way it looks in the Tacoma. I think it looks better than the stock head unit.
One other thing worth mentioning -- if you happen to have an iPhone, you can use MotionX for GPS instead of the expensive GPS module.