Step 2 is unnecessary. It breaks the relation between the basic dimension entities.
When you use Properties on the dimension direct, you can enter a label which will replace the value.
With intact relations it is also possible to modify the selected dimension.
In selected state there are various blue dots which could be dragged with left mouse button to modify the existing dimension.
When the X/Y ratio of the drawing is okay, you can also play with dimension settings in Current Drawing Preferences.
There is a Length Factor, which will be applied to all dimensions.
E.g. enter
100/120 as Length Factor and the 120 unit dimension will display 100.
And all other dimensions will be scaled by the same factor too.
Or select all and use Modify -> Scale to make the drawing 1:1 size.
This will change dimension labels too.
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