Two toughest things will be where the extension pipe bolts to the cat, and the hangars. Hangars are 12mm and cat is also if memory serves, the easiest way is of course by using a tourch, but I guess it can be done by hand. Rust is your main issue, wear safety glasses or you will visit E.R! Heat or cut bolts I think Toyota uses studs in the cat, if not too rusted and enought threads are still good, they can be re-used, if connector pipe runs under rear axle, the entire thing can be dropped in one section, if it runs over the axle(unlikly) cut it with a hacksaw. Using an air impact with tight fitting socket may help!