To fix or assemble something in a slapdash manner, generally straying from the accepted method of doing so, especially if materials are used which are also foreign to the process.
Orlando's pool table isn't level, so he niggerrigged it by putting a stack of newspaper under one of the legs.
Tyreese didn't have an entertainment center for his newly "acquired" high definition television, so he decided to niggerrig one by using cinderblocks he acquired in a similar manner from a nearby construction yard.
To perform the poorest quality repair job imaginable. To nigger rig something that is broken requires that you put the least possible amount of effort into the repair job, using the poorest quality materials available. A nigger-rigged job is instantly identifiable, usually due to large amounts of duct tape or wire covering the broken item. Also known as "Afro-engineering".
Niggerrig. What Obama is doing to the economy.