Spark Plug Change from Under The Engine?
 

I wanted to know if doing the plugs and coils from the bottom of the engine is an alternative way of doing them? I need to install my UEL again and if my stock header is off is there more room?

nope, but doing spark plugs is a cake walk when you jack of the engine. Jack up one side, swap header and plug, jack other side swap header plug and done.

Unfortunately I don't think going from underneath is any easier than shoving your hand from up top. You might be better off unbolting two motor mounts and jacking up the engine a few inches, I hear it makes a world of difference. You will want to check a YouTube video of someone doing this to see if it's best for you.

I cannot speak from experience. I was able to replace my spark plugs with the engine out of the car during a body shop repair.

I can say from experience, ignore the first YouTube hit where some dude swears you can do it without jacking up the engine. Maybe you can, but it's not worth trying.

1) Put at least the front on jack stands
2) Remove the two motor mounts on the bottom
3) Jack up one side at a time from the head, or headers right under the head
4) Have faith that your harbor freight hydraulic jack won't fail while you replace the plugs one side at a time
5) Don't forget to re-secure the motor mounts

A couple of inches worth of lifting makes a big difference in being able to get the coil packs and plugs out. Having an assortment of ratchet attachments and u-joints also helps. A rubber jack pad is also nice to have to avoid metal-on-metal and the possibility of slipping.

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Just did the entire procedure with jacking up the engine. It honestly was not that bad and it was so easy.

I found that I got a little better access by removing one motor mount bolt and just loosening the other so that the engine would tilt the desired side up.