Com : taptap : 3 very dangerous things done here. 

1. Loosening the strut plate without first compressing the spring. Good way to have a spring pop off while removing nut and seriously injure or kill.

2. Grinding on a strut. If it is still pressurized, then you risk grinding through and causing strut to explode.

3. Welding on a strut can cause 2 things to happen. First, cause the gas inside to heat up and expand and ultimately causing the strut to explode. Second, causing a hole to form in the strut and explode.

Do not attempt these things you have seen in this video. It is very dangerous and could cause serious injury and/or death to yourself or another!!!!!