Check engine light. Have code, now what?

I have a 2003 Dodge Ram 2500 5.7L Hemi. It has 45500 miles on it.

The check engine light came on the other day. Took it to Advance Auto Parts and ran the diagnostics. Came up with the following code:

P0352 Ignition Coil B Primary/Secondary Circuit Malfunction.

I am selling the truck and do not want any issues to arise, but I also do not want to put any money into it. I spoke to a local Dodge tech and he said that with all the snow and melting snow, it probably got wet and had a misfire and not to worry about it as long as it was running fine - it is running fine. After initially clearing the code, it came back the next day. His suggestion was to "unplug" the battery to clear the computer. Does this sound reasonable or is there more to it than this?

If I need to replace the part, is this something that a novice could do themselves? If so, how?

I also wanted to mention that I have an 8' Fisher plow attached to it.

Thanks!