somebody

[AirbusA321]

Can "somebody" be replaced with "someone", "anyone" and "anybody" without changing the meaning?

1 Could somebody please explain to me what's going on?
2 The engine is damaged. We need somebody who's able to repair it.

 

[J&K Tutoring]

None of your options would change the meaning, but anything but someone would sound awkward.

Someone and somebody are interchangeable. Anyone and anybody are interchangeable.
Your #1 could be acceptable as: Can anybody/anyone explain to me what's going on?
Your #2 can substitute someone, but would have to be completely rewritten to accept anyone/anybody.