Replacing a bike pedal is in theory a simple enough task, but over time the threads can seize and may require a lot of force to release. When attaching the new pedals, take care not to damage the threads in the crank arms. Replacing damaged cranks can be expensive.
This is a long guide, so you can choose to either watch the entire video above, or follow it in smaller chunks by clicking on the individual steps below.
Steps to Replace A Bike Pedal:
If the bike pedals are single sided you can tell which is left and right. Double sided pedals are marked - either on the flat end of the axle or beside the 15mm flats for screwing them on. Modern pedals are always marked 'R' and 'L'. Older French or Italian pedals may be marked 'D' and 'G' or 'D' and 'S'. The material of the pedal axle is usually harder than the material of the crank so take care as it's easy to damage the soft thread of the crank.