The Second Tunnel by Radu Cinamar

So on page 64 he gives a great explanation on how to enter the inner earth . Here is a summary for you!

Simple step by step guide to getting inside the inner earth:

Step 1: Get in a boat and sail to the poles of the earth.

Step 2: Point the boat in the direction of the magnetic field

Step 3 : Drive the boat to the point where the magnetic field is strongest and aligned with the gravitational field.

Step 4: Drive the boat at a constant speed ( not fluctuating)

Step 5: There is a point where there will be a shared resonance between bodies frequency and magnetic field. This means the frequencies will be matching.

Step 6: Then as you enter the magnetic cone the intensity of the field will get lower and your bodies vibrational frequency will get higher.

Step 7: With all of the above you will pass to the etheric plane along the magnetic field lines.