Translation according to my knowledge:
To carry out the plan depends on (視乎) action.
Never fluctuate (動搖/變動) with determination (決心).
Step by step keep going forward (向前,adverb) of the direction.
I will make a success (成功,noun) that is my affirmation (斷言/肯定)!
執行計劃靠行動------ To start or opreat a plan, action is needed.
決不動搖---Never change your mind. Or Holding on your mind/ Decision.
一步一步向前走-----Step by step to get forward
我定能成功-----i will be success. or i must make it.