How hard is it to change a boiler/water heater?

[ps]

I have a about 4-1/2 feet tall boiler, seems about 20 years old, that heats the water only to provide hot water in my garage. I was just looking at it, and seems I just need to undo the valves using a wrench and no soldering of the pipes seem needed. How heavy is this thing, can I move it and when it's empty by myself and, if I do decide to hire someone how much is a good price for the labor.

And, what's causing the my hot water to come out brown, We've replaced all the water pipes to copper last year, and I flushed out the boiler day after the pipes were changed.

peter.

[Generic Male Homosapien]

Someone may have connected the toilet drain to the water heater. Check that first.

[basilnospam]

Well,there is a great deal more information needed about the installation. Is the water heater/boiler gas fired or electric heated? What is the diameter of the heater (assuming it is round)? Water could be coming out brown because the interior of the boiler is corroding. This could be due to the water quality (or lack thereof) in the system. It could also be due to galvanic corrosion caused by dissimilar metals (copper pipes and iron/steel boiler). Labor costs will vary depending on the location and the difficulty of the work. Without more information, it is impossible to give you an estimate.