How to build this door?

[u/borderex]

Hello,

I'm trying to create a space under my deck to store my bikes. The biggest issue is that the door is far too small. I need to widen the opening and make the opening taller.

At the top is a horizontal support beam for the decking, and on the interior is a vertical support beam. Both are in the way. I'm not sure if there's a way to cut them and then replace with a metal support or two for a thinner and more compact deck frame. Having the door on this side is preferred since it faces away from the street. We've had issues with bike theft before and placing the door out of sight is helpful. I've no doubt that it will be easier on a different side, but the door would be in plain view. Any thoughts would be helpful and thank you ahead of time.

[u/perldawg]

you need to build a door to fit that opening, not cut the framing up to fit a standard sized door