Modify Residential Floor Plan in AutoCAD

I have an existing residential house floor plan in AutoCAD DWG format along with a PDF/reference drawing.

I need an experienced AutoCAD 2D drafter to make several modifications to the existing drawing. I do NOT need a new design from scratch.

The work will mainly involve:

Modifying existing walls and room layouts
Adjusting dimensions and positions
Copying/repeating existing elements between floors where required
Making stair/layout modifications
Adding or removing small drawing elements as instructed
Keeping the existing drawing structure/layers as much as possible
Maintaining accurate dimensions and alignment
Delivering the final editable DWG