Recommendations for minor renovation

Start with the super. He or another building handyman might take on a relatively small job like this. If not, the super can probably recommend a GC that's worked in the building on a similar job and you can easily go check out the work. Also check out your building's alteration agreement. Many co-ops require shareholders to replace the bathroom risers when re-tiling floors and walls. Try ABC for the shower doors. They'll come on site and measure and install. miguel@abcshowerdoors.com

I pasted the discussion about my shower door issue because I agree that sometimes you need to hire a shower door company instead of relying on the building handyman:

http://streeteasy.com/nyc/talk/discussion/31566-recommendation-for-shower-door-repair-company

If the majority of your work is in the bathroom, you might investigate some bathroom renovation shops to see if they have in store staff to take on this project, but I would want to see some of their other apartment projects before I hired them. The only problem I foresee with using the building super is that it might be difficult to check out his work in other apartments without offending him if you don't like his work and don't want to use him for your project. Probably the building super can recommend a contractor to take on this project, but you would need to be somewhat flexible in terms of their availability if this project is smaller than their typical jobs.

I think the building super can likely handle the removal of the built in shelving unless you are replacing it with another built in piece and then the carpenter can take out the shelving for you I would think.

I had several small renovation projects in my apartment and I basically worked with either shops or designers directly for each project. I chose not to hire a GC, but it involved me being very involved with each project.