Is there an aid or a trick to help get mating parts together?

Our parts are meant to have a very tight secure fit to reduce any pinch points. Please make sure you follow instruction sheet exactly and we suggest two people for assembly to help with leverage, force and movement. Brush some vegetable oil onto mating parts to aid as this will allow parts to slip/fit together easier and use a lot of downward force when pushing parts together during assembly. Another trick or suggestion is to use blow dryer and heat up the plastic to make it plastic more pliable when pushing or forcing parts together.