I need a new motherboard for my emachines desktop. Is this something I can replace myself?

My emachines T6420 desktop is essentially dead – black screen and fan on full blast. I poked around on the internet and from what I read that I need a new motherboard. I have found one for $99. Before I order it I want to know if I can replace it myself or if I do I have to take it to a repair shop. Money is very tight right now so a $99 repair is better for us than a new computer. Now if I have to pay an arm or a leg for labor that is another story. Will the board come with detailed instructions?

All HELPFUL suggestions are greatly appreciated. If you just plan to knock emachines, don’t bother… it won’t help me. Thanks!