How do I install a new motherboard?

How can I install a new motherboard? It's an old HP a000, so will it fit into the case? (more details below)?

• I need a faster motherboard for my old computer and need to know how to install it. Is it difficult to install? Also, how do you instal two video cards? I have a 400w and 300w cards, so would I have to get a 700+w power supply?

• Answer:

  its not that hard but you cant just upgrade only the motherboard also check your processor and rams to make sure they are match for the new motherboard and you should get little bit better power supply like 850 to 1000w. to install the two graphic card you need to make sure that the motherboard has two pci express slots. and a depends on the video card brand like amd or nvidia, you need a SLI(nvidia or Crossfire(AMD) bridge to attach the two graphic cards together and also make sure the both graphic cards are the same brand otherwise you wont be able to attach them together