Is it easier to pull both motor and trans out from top to replace trans

Out the bottom maybe.

front wheel drive ? probably yeah , U toob has many videos on a variety of car repairs , replace rear seal on engine and anything else accessible

The Impala is rear wheel drive? Take the drive train out the top at an angle and separate the tranny on the ground- idk, did I miss something? is it FWD? The Guru is a little confused today by all these scary masks- are they MASKS?!

2000 up/newer are Front Wheel Drive. Its easier to drop out the bottom with both engine & trans attached, but will need a way to lift the car off the assembly or have a car lift and use something to support it with and then lift the car higher and move the engine/trans assembly out from under it or while car is raised you need a way to lower assembly down from the car, assembly has the whole axle(s) to wheel(s) still attached. Then when on the ground/stand you work on what needs done.

On the youtube video's I just watched they are removing just the trans from bottom, get a repair manual for procedure.