In case you are referring to the new https feature for IISExpress with the 'LansweeperWebsite' certificate that comes with 5.3.x versions
1) Make sure you are using IISExpress
2) Stop the IISExpress service
3) Go to the lansweeper IISExpress certificate install folder
(ex. C:\Program Files (x86)\Lansweeper\IISexpress\Certificate)
4) Rename the 'LansweeperWebsite' certificate there to something like 'LansweeperWebsite_Backup'
5) Rename your own certificate to 'LansweeperWebsite' and place it in the folder
6) Start the IISExpress service
Kind regards