Converting XML file from v 3.2 to 3.3

Hello Community

I have a question and I was wondering if you could kindly help me with it.

Currently we are working from OJS version, but some of our publishers are still on the 3.2. When we want to import articles and issues, it seems that they are not compatible with 3.3. now a method for converting XML from an (old) OJS XML format to OJS XML format applicable to our version of OJS is needed.
So I was wondering if anyone has any experience with converting them to 3.3 before importing them to their system, or if there is any other ways to do the same job.

I am getting these types of errors:
Element ‘{}article’, attribute’date_published’: The attribute’date_published’ is not allowed.

Element ‘{}article’, attribute’section_ref’: The attribute ‘section_ref’ is notallowed.

Element ‘{}article’, attribute’seq’: The attribute ‘seq’ is not allowed.

Element ‘{}article’, attribute’access_status’: The attribute 'access_status’is not allowed.

Element ‘{}title’: Thi selement is not expected.
Expected is one of ({}id,{}submission_file,{}pkppublication,{}publication ).