You simply need to sit down and get your hands ready for the following steps. The video below offers a visual demonstration, so I recommend checking that out too.
1. While sitting with your head and body on about a 45 degree angle, turn your head sideways and rub your sternocleidomastoid muscle downward four or five times. You can find the muscle right beneath your ear running down your neck to your collarbone. See image. Do this on both sides of your neck to help relax your neck.
2. Take your index fingers, locate the hard, bony part of the upper sides of your nose, and move downward toward the soft part on the side of your nose where the bone ends. Begin massaging this area in a circular motion with as much pressure as you can for about 20 seconds. Once completed, rub the muscles from the side of your nose down and toward your cheekbones to relax them.
3. Take your index fingers and run them under the inside orbit bone above your eyes until you find a notch in the bone called the super orbital notch. It is usually just above the centre of the eye. Massage that notch in a circular motion with as much pressure as you can handle for about 20 seconds. Once done, massage your forward with both hands starting in the centre of your forehead and pulling outwards towards your temples.
Once you have gone through this process you should notice a lot of relief in your sinuses and should be able to blow your nose quite easily. You may have to repeat this process again, but play with it and see what works for you.
Below is a video from Dr. Adam explaining the entire process. I have also included another helpful method that worked well for me as well.