Since you followed this tutorial I guess you use LDPE... so it is simple:
- Calculate your scaling factor
- reset orientation and origin of manipulator
- Select the entire sticker (ctrl+A)
- Action -> scale selection -> fill in X and Z scaling with the factor previously calculated (and let Y scaling at 1)
- OK
- Calculate your scaling factor
- reset orientation and origin of manipulator
- Select the entire sticker (ctrl+A)
- Action -> scale selection -> fill in X and Z scaling with the factor previously calculated (and let Y scaling at 1)
- OK