It is recommended to use the standard way to remove/install add-ons in NinjaTrader.
The most recent versions of all add-ons are always available to download from the homepage.
Download the latest assembly (DtBuySellPressure.zip file) from this description page or from the homepage.
Run NinjaTrader 8.
Go to 'Tools' → 'Import' → 'NinjaScript Add-On…', select downloaded .zip file and press 'Open'.
Click 'Yes' when asked for replacement of the existing "DtBuySellPressure" and "DiscoTrading.Net48.Common.dll" assemblies:
Restart NinjaTrader 8!
Note: Various Dt add-ons are relying on the same "DiscoTrading.Net48.Common.dll" library. The new build contains the most recent version of the library, so you have to click 'Yes' when asked for replacement of the file during installation.