Effect Pedal Modifications

Hello all I am knew to this site but have some questions for all the electronic buffs here. I am wanting to know where I can find mod pages for my effect pedals, free ones. I found some places that offer mod kits or modification of my pedals for a price but I do electronic work myself. I dont want to pay for something I can do. I just need to find out what to change with what value or type of part. Thanks for any and all help. :)