You need https://www.amazon.com/FootFitter-Premium-Professional-Stretcher-Stretching/dp/B000PMKBL6/ref=sr_1_8?dchild=1&keywords=boot+stretcher&qid=1623945298&sr=8-8. If it still doesn't work out after a few days of stretching each boot, then you can always return everything. Personally I've had to get boots 2 euro sizes up from my street shoes size (from 44 to 46) for my Alpinestars SMX Plus V2's to fit.