IMHO, the legal, Constitutional remedy is “impeachment”, IF it can be proved that Joe Biden was part of the conspiracy to steal the election.
Please do not take the following as me being sarcastic, but the Congress was also part of the conspiracy to steal the election, so why would they vote to convict and remove Biden or even vote for articles of impeachment in the first place ?
And even if we take back the house next year, there is no way we will have 75% of the Senate, which would be required to convict and remove the President.