Listed below is the process of driver's installation in Windows8.1 as an example.

 

Step1 Pairing

Make sure your printer is turned on.
Make sure Bluetooth on the PC is turned on.
Choose Bluetooth icon in task tray on Desktop。Then you will see menu of Bluetooth.

Choose "Add a Bluetooth Device" in the menu.
You see "Manage Bluetoth devices" screen and  "Mobile Printer / Ready to pair" shows up there.
Choose the "Mobile Printer" and press "Pair" button. If PIN code is required, enter "0000".
Now you see "Mobile Printer / Paired".

Step2 COM port number check

Choose "Open Settings" from Bluetooth menu of Bluetooth icon in task tray.

Choose "COM Ports" tab to check what COM port is assigned to "Outgoing".

 

Step3 Printer driver installation

Execute the printer driver installer.
During the installation steps, you will see the screen to choose/set "OS" and "Code Page and Printer Port".
You need to put the COM port number which Outgoing is assigned as checked above.
Also when you see "Using Bluetooth(SPP)" dialog, choose YES.

 

After the above installation process, check whether to find the icon "Mobile Printer" and driver's name
in the "Devices and Printers". Choose the "Printer Properties" to check the "Ports" tab and to try "Print Test Page".

 

Make sure to use "Uninstall a program" on Control panel to uninstall the driver.