Hey guys,
So I'm doing my first build. Got everything I need, but for the life of me I can't figure out how to get this new out-of-the-box bottom bracket into two pieces to install!!!!! I have a bmx background so I understand how these things work, but it's a different world. Is there a lock ring on the left side I need to remove or something? For context, its a 68 x 103 sealed going into an Aventon. Thanks in advance!

Not enough information. What type/model bottom bracket? What type of frame/bottom bracket shell?

X-Speed 68 x 103 JIS square taper

Aventon Cordoba; 68mm english.

I'm not familiar with "X-Speed" bottom brackets and can't find anything about them on Google, but in general, cartridges designed for square-taper cranks will have at least one and sometimes two removable cups or mounting rings. If only one side is removable, it's usually the non-drive-side and you'd start by removing the non-drive-side cup or ring and threading the cartridge into the frame, keeping in mind that the drive side threads on an English thread bottom bracket are left-hand and tighten counter-clockwise. You may find it helpful to start the non-drive-side cup after the drive side has engaged a thread or so, just to help keep things lined up. Tighten the drive side in all the way -- there may be a proprietary tool required to do this. Then snug down the non-drive side cup.

If both ends of the cartridge are removable, take them both off, slide the cartridge into the frame and start threading the cups in place to hold it. Again, a proprietary tool may be needed for this. Cartridges with both ends removable allow you to fine-tune the chainline as you tighten things up, so make sure you have things lined up properly before snugging things down firmly.

Looks like a pretty standard Shimano style cartridge bottom bracket. You will need a tool to tighten it into the BB, can't tell what type from the City Grounds website as they only show the BB edge on, but I would guess it's this:

Park Tool Co. » BBT-22 : Bottom Bracket Tool : Bottom Bracket

Does this video help?

https://www.youtube.com/watch?v=_Kf-V5iulaU

Thanks for the response! Yeah the non-drive side has the removable cup. The issue is that removable cup seems to be stuck. I can't get it off from the rest of the assembly! Everyone I've spoken to about this has said that they've never come across a new one that came assembled and wasn't very simple to pull apart. It must be realllyyyy stuck on there.

Maybe invest in a BB that costs more than $10? Shimano UN-55s are very reliable and cheap.

Sometimes the removable cups, especially when made of metal rather than plastic, can become stuck on the BB when it's not installed on a bike. Try putting your splined bottom bracket tool into the removeable cup and then grab the middle of the BB with a pliers or vise grips and turning. You don't need to worry about scratching it since you'll never see it anyway.

The DS is probably part of the cartridge. It doesn't need to come off.
Screw the BB in from the DS part way.
Start the NDS cup.
IF the NDS cup is plastic, I'll usually screw it in all the way first.
IF metal, I'll screw it in last.

Thanks! I will definitely try this. Good call on not worrying about the scratches.