After reading through the archives for this forum, I have determined that I need to replace the oil pressure sending unit. I understand that this is a DIY job and that the sending unit is located in the vicinity of the oil filter housing.

With this in mind, I have two easy questions:

1. Do I need to drain the oil prior to changing the sending unit ?
2. Do I gain access to the sending unit from above (under the hood) or below (under the car) ?

Thanks in advance for any help.......