Don't, do this instead to fuck up their data and actively harm reddit's value when they go public.

Copied from there:

• [Choose 1/3] Open Zompist’s gen. Take off the line saying “ki|či”, and click “Generate”. You’ll get some random babble like “Bepe topioi kabi brete i kropra”, copy it somewhere.
• [Choose 2/3] Open https://sebpearce.com/bullshit/ to get an entire bullshit article
• [Choose 3/3] Open https://nonsense.x2d.org/ to get a bullshit sentence, i suggest getting a few ones.
• Open your Reddit profile and drag the button of Power Delete Suite to it.
• [Optional] Check the box saying “prepare local backup of items”, if you want to save your content elsewhere.
• Uncheck “remove comments”. You want to replace them with babble, not remove them.
• [Optional] uncheck “remove posts”. It depends if you post mostly self posts or if you post links/pics. Use your reasoning.
• Check “Edit comments / self posts”. It should open an input box for text; place the babble from Zompist’s gen there. Then click “process”.
• Just wait!
• [Optional] Click to download the backup of the items.

Let others know!