Hi friend, here is how to proceed : (alfresco_root being the convention to name your alfresco installation folder like C:\Alfresco or opt/Alfresco)
1- Shut down your Alfresco server and make a backup of you WAR files in Alfresco_root/tomcat/webapps (share.war ; alfresco.war)
2- Copy share-site-creators-repo.amp in Alfresco_root/amps
3- Copy share-site-creators-share.amp in Alfresco_root/amps_share
4- Install AMPs by going to Alfresco_root/bin
for Windows : execute the file apply_amps.bat
for Linux : execute the file apply_amps.sh
5- Let the script run,(you'll be eventually prompted to press a key) it will automatically install your AMPs.
6- When it finishes, youll be informed that your AMPs were applied successfully. In the same folder, execute clean_tomcat.bat or clean_tomcat.sh depending on the OS youre using (this prepares the WARs to be redeployed at tomcat restart).
7- Start your Alfresco server and follow the instructions supplied with the extension to use it.
8- Enjoy!