Upgrading Drupal

Hi i am looking for some advice on upgrading in a certain situation.

I have taken over a site which has been developed externally from my company. The problem i have found is that the company which developed the site customised quite a few of the modules which they firstly haven't documented and even worse have made these changes to the source code of the modules in question rather than using the hook system or overriding the theme templates.

Hi ,

I have to upgrade the version of drupal from 5.10 to 5.20 for a running live website, please help how canI upgrade, is there risk of data loss, can anyone just give m the step to upgrade the verison without any problem.It is very urgent.....

Thanks and Regards
Nitin

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