Most manual transmissions are easy to change however there are a couple of things to be careful about, the first is that there are many types of fluids, most manual transmissions DO NOT use 90w gear oil anymore so be sure to check your manual or check with your transmission man on what type to use on  your car or truck, another thing to be careful of is when pulling the drain and fill plugs that you pull the correct plugs and not make the mistake that many, many people have by pulling the bolt that is really the reverse idler pivot pin, when this happens the inner clip pops off and you lose reverse! So just drain and fill and call your Transmission Man if you need any help