Imperative, infinitive or impersonal in user instructions?

When drafting or translating instruction manuals, you must decide which verb form to use for user actions. In a step-by-step procedure, should we write “Remove the lower cover” or “To remove the lower cover”?

Short answer: both patterns are used and both can be correct. Whatever you choose, keep it consistent throughout the manual.

Imperative (recommended in English procedures):
Clear, direct and usually shorter.
Example: Remove the lower cover.
I generally prefer the imperative because it tells the user exactly what to do and how to do it.
Infinitive:
Seen in headings, UI labels, maintenance cards, and in some house styles for lists of actions.
Example: Remove the lower cover (as a bullet or heading), or To remove the lower cover (as a section title).
In running text for numbered steps, English usually prefers the imperative.
Impersonal / passive alternatives (use sparingly):
They can sound longer and less explicit.
Example: The lower cover must be removed.
Use when responsibility must be de-personalised or when stating a requirement rather than issuing a step (e.g., safety/compliance notes).

Tone note: in signs and safety panels, the imperative can feel brusque; many styles switch to must + verb (“Do not smoke” / “Smoking is prohibited”) or to a passive prohibition (“Smoking is not permitted”) to suit the context.