Once a planning of working hours for a project has been made, there are several ways to edit it.
From the calculation of a deliverable for a project
From the options of a project
From the overview of the resource planning
From my planning
View and edit the planning of a project by clicking the Planning button. This shows the planning for the project per week. Tap a deliverable to view its activities and resources. Tap on a resource to edit his/her planning for this week.
You can edit the resource planning overview by tapping on a cell on the grid. This will open a window where you can edit the hours of that resource in that week/day. Adding a new resource to the planning is not possible here; do this via the calculation. The project planning overview cannot be edited.