Where are comprehensive instructions?

Where are comprehensive instructions?

Good morning, 
I've just joined a company that uses Zoho People, and have been tasked with documenting our processes for our HR staff. I am having difficulty getting acclimated with the application. 

I have reviewed the User Guide on the support site, however I cannot find some key information. 
i.e. 
- Instructions for an Admin to approve a PTO request
- Instructions for an Admin to remove a previously approved PTO request

Any help would be appreciated! 

Thanks, 
Laura