Broaden your perspective is simply another way of saying 'raise your vibration'. This is about stretching yourself in a whole new way.
When we distrust or resist perspectives, we send the energetic message that certain points of view are invalid, unacceptable or beyond recognition. Since the natural inclination is to be open to receiving waves of energy in the form of new perspectives, discomfort indicates we are not allowing ourselves to expand. Letting go of resistance is about seeing all perspectives as valid. This does not mean we have to adopt or agree with all perspectives. To open up and allow energy to flow, we simply need to accept them as valid.
Notice where you feel muscles tighten, when the physiological message of reistance is coming through. This is an opportunity to see energetic messges you give yourself and to reverse the conditioned resistance.