After cleaning both surfaces and gluing them together there was no adhesion whatsoever on the sole part. Augmenting that the warpiness of the sole does not make it easy to adhere. After calling Alpinestars they mentioned that they add a special primer to the sole to have adhesion on both parts. This primer is not included in the kit.
Solution: I had to ship the boots directly to Alpinestars for them to do the job.