Looking at the table in clause 90.2, it is the Contractor which is terminating for one of Reasons R1 to R10 ... I am both not an insolvency practitioner and, if I was, you haven't given enough detail to establish exactly which of the reasons it is.
Regardless, Reasons R1 - R10 have the same procedures to go through P1 and P4 and the same amounts due (A1, A2 & A4).
P1 is in clause 92.1 : the Employer may complete the works and may any Plant & Materials to which you have title e.g. paid for and marked if outside the Working Areas or it is within the Working Areas (see clause 70.1 & 70.2)
P4 is that the Contractor leaves the Working Areas with their Equipment.
I could go into the detail of the amounts due, but I won;t so what should the Termination Certificate state ?
I would thought a 'Termination Certificate' contains who is terminating Party and the reason for terminating which is matched to one of the Reasons in the contract. Then a short statement, saying something like, as a result, in accordance with the table in 90.2, the procedures to be followed are P1 and P2, and the amounts due A1, A2 & A4. Details to be agree.