How to upgrade my videocard in a Lenovo Thinkcentre m58e?

I want to be able to play World Of Warcraft. I'm assuming I can even play it with the rest of the components.

Additionally, does anyone have any tips with what videocard to upgrade with?

It really depends on the model you have. Apparently the Thinkcentre m58 was put out in different cases. One was a standard desktop case and the other a slimline case. If you have the slimline case, then you need to buy a slimline (low profile) pci express video card. If you have the full desktop case, then pretty much any pci express card. I would like to point out that in buy a new video card for your computer that you need to look at the maximum power consumption as this will be a major issue with you unless you have upgraded the power supply.

If you're not sure how to do this look at the links in sources.