deep crease in left side panel

Are you able to weld ? can you cut steel? This is not an unbolt and bolt new piece in type of job replacing box panels is a long and time consuming job that requires a certain amount of skill in metal fabrication and welding skills. Then once the panel is replaced there is a certain amount of body work required to massage the panel into a smooth contoured shape that it was as when new . Then you need to repaint . this is a job for someone with experience in this field . If you dont care how it looks then crawl in under the truck and find the dint or crease , have someone hold a hammer or dolly on the outside along the crease and from the inside have at it with a hammer tap out the damaged area as best as possible then remove the paint and fill the dints with bondo to smooth out the surface. once you have it to you liking paint. Hope this helps