Hi,
You will need to register for Self Assessment, if you have not already done so.
Register for Self Assessment
You would need to complete SA100, the main tax return, 2022 and SA109, residence, remittance basis, 2022 to claim split year treatement. You will also need to complete any other supplementary pages appropriate to you.
You can download and print off the tax return here:
Self Assessment tax return forms
Thank you.