That is actually very common. Many people struggle with step-by-step instructions. The best way to tackle that is to have the instructions while you are using them, instead of trying to memorize them and use them at a later time.
However, you can improve your memorization skills. It's best if you pick a topic. Say, you want to learn how to build bird feeders, so you keep at it and keep at it until you develop a solid understanding of how they are made. This leads to better memory, because you are reinforcing your memory. But it only works with bird feeders and other similar projects.
If you are using WikiHow like an encyclopaedia, you are far less likely to remember step-by-step instructions. But all those foggy memories do add up, even if you can't use them how you would like to. The more you read and the more you understand, the better your skills are in general. Your improvements may seem invisible, however, they are stacking up. It just may not seem like it.
The forgetful historian may not remember what happened during World War II, but the more he studies, the more he betters himself.