Migrating from OJS 2.2.1 to 2.4.6

I run an OJS 2.2.1 I’m getting some errors since nearly a year ago. I don’t quite trust a sequential patch-based updgrading, as my 2.2.1 version code was customized by a former sys admin we had on the team.
I have installed a new clean OJS 2.4.6 and intend to export database from 2.2.1 to 2.4.6 using the command line tools
Is this the best approach, or should I try a sequential patch-based upgrade from 2.2.1 to 2.4.6 regardless the very likely customizations formerly applied within my 2.2.1 code?
Any suggestions?
Thanks in advance for your help.

I think your approach is correct. I strongly recommend package upgrades over patch-based upgrades.

For best results, download the stock copy of OJS 2.2.1 and then use a tool such as diff ( http://man7.org/linux/man-pages/man1/diff.1.html ) or winmerge ( http://winmerge.org/ ) to see the changes made by the prior administrator. Local customizations can be readily managed by version control such as Git or Subversion, if desired. Always start from a place of the stock functionality, however, and evaluate any custom needs from there.

Thanks for your reply.
I will try your recommendations. I guess I will probably need some more help during the process. I let you know how I’m doing.