Matchy42

Ok so I know this has probably been covered many times in the past but I have spent days researching this problem to no avail. Sooooo, I have a Stagea M35 with the VQ25DD ( I know there is the wagoneers topic but this is VQ related ) Brought with a broken motor due to timing chain issue which snapped one of the ends of the camshaft off. Came with a second "Good" motor which we have put in but have been having trouble with the timing, specifically the vvt intake cam on bank 1. We found shortly after we put the motor in the vvt was having problems, took off cam covers to find the spring had jumped of its placing. This was due to the fact that one of the stops (of how much rotation the vvt could do) had broken off. So we replaced the spring and thought we'd see how long it'd last with only one stop, apparently not very long. So now I'm at a point where I have to replace the whole vvt part of the bank 1 cam sprocket, so my questions are: Can this be done just by removing the allen keys at the back and two bolts off the end of the sprocket/cam? take it off, find the timing marks and put it all back together? Can you do a timing chain job with the engine in the car? I'm assuming yes but a bit of guidance would be great. And any info on the car such a service manual links / other topic links. Also do the electronic clutch part on the cover wear / have trouble? can you get new ones from nissan does anyone know? Thanks.