Hi @yannickgriffon
Here's the [https://download.lenovo.com/pccbbs/thinkcentre_pdf/m73_hmm.pdf|hardware maintenance manual] for the desktop.
Go to p.209 to view the procedure to remove/replace the HDD.
***''Note:''*** p.185→ in the manual deals with the replacement of components for the Thinkcentre M73 TFF desktop as selected by you. Machine Type (MT) 10AX, 10AY, 10DK, 10DL, 10DM & 10DN. Check the product information label on the back of the desktop case to confirm the machine type of your computer
There's plenty of information online on how to [https://www.google.com/search?client=firefox-b-d&q=relpace+and+clon+desktop+hdd+to+ssd|replace and clone desktop hdd to ssd] i.e. videos, written instructions etc.
Usually the more reputable suppliers of SSDs will also provide a link to download free cloning software (link URL and password information supplied with SSD).