I would suggest that you have the Factory Shop Manual for your car before you start this job. It can be done but it will be quicker if you are methodical about marking lines and keeping fasteners in small marked boxes with good notes... and in the order which you take it apart...

Are you sure it is the evaporator leaking the freon and not the connection with the expansion valve ? That would sure be easier to fix !

Are you going to get a new one or a used one to replace it if you need to ? Be sure to pressure test either way... what a bummer it would be to get it all back together only to find the new one had a leak also....

PS, you can not smell the freon. You may smell algae and fungus in your evaporator box.... you might try an immediate spraying of Lysol spray disinfectant into the intake opening with the motor running .. several light sprayings over a couple of days may cure the smell and you need to be sure your water drain out of that box is "perfect" to use the FSM word....
After you have killed the growing things then spraying with Febreez may be helpful...