Add Job Steps
1. In transaction code SM37, click on the job which you wanted to add the job steps. Go to Job > Change. Click on Step (Define steps F6). Then, go to Step > Create.
Delete Job Steps
1. In transaction code SM37, click on the job which you wanted to delete the job steps. Go to Job > Change. Highlight the step then, go to Step > Delete.
Consider there are 100 steps in X job, is there any way to delete multiple steps (1st 50 steps) in one go?
I never done it before. But, you can check the SAP Note 1532884.
Or, you can try to delete them from SQL (Oracel, MSSQL).