I have a very nice 2004 g35 coupe with 85 k miles on it. Have owned it for 14 yrs. But since last season the ticking is becoming annoying. I believe because of a leaking valve cover seal and lack of lubrication in that one location, the lifer bucket and camshaft are worn slightly more than the other valve bucket locations. Has any forum user performed fix DIY. Can I use a thicker oil, with new valve cover to rectify this tick before going directly with the big fix, ie: remove timing chains, camshaft, and REPLACING lifter buckets.

Valve cover will just cause an oil leak, it shouldn't starve a lifter of oil unless the leak is BAD. For a DIY, you're probably best off searching for cam upgrade DIY's where owners install aftermarket cams. Check for exhaust leaks and vacuum leaks as well & rule them out.

To replace the lifter/bucket, you need to remove the cam(s). Thats a lot of work, and there are a number of other parts you may as well replace (at least inspect) while you're in there (timing chains, guides, tensioners, water pump, etc).
Plus these are a solid lifters. You need to record the lash clearances prior to disassembly so you know what spec lifter(s) are bad/out of tolerance, and calculate the desired clearance lifter to order up & replace them with.

You can try a thicker oil, but odds are it won't make much of a difference. My G with over 250k ticked quite noticeably. I tried 10w-30 and 5w-40, and only the latter made a little difference.
I went back to 5w-30, as the oil pressure was above OE min spec (28 psi hot @ idle) & I was able to live with the ticking.

Thanks for the reply. Just another question regards to where you purchased your parts from. I’ve used rock auto for a number of parts. Any suggestions where to get engine parts.

For timing components and water pump, I'd recommend you buy OEM, especially if you plan on keeping the car a while.
Z1 and ConceptZ both stock a lot of OEM parts, usually competitively priced too.