There are situations in life when you need a break from Steemit or can't have access to Steemit for a long time. But suppose you already had a large following on Steemit and want to keep your fans happy (I am thinking of many typical YouTuber and Co.), you could pre-produce content and have it posted automatically using certain tools or you could appoint a representative of your trust for that time, who can then also comment and vote in the name of the Steemian.
After the representation has been replaced by the actual Steemian, he can delete this posting key and simply continue to use his own.
Suppose you have a project involving several people (e.g. 
I recommend using Docker to avoid installation and environment problems.
This tutorial works with docker run -ti maxpatternman/steem-python-base:0.18.3 bash.
This should also work with Windows 10 and the PowerShell.
This tutorial focuses only on the most important points of creating and deleting the posting key. So it is also suitable for inexperienced users who only want to use this function or who want to deal a little with steem-python or Steempy.
Open your terminal and enter the following command:
1.1. steempy addkey
1.2. Now Private Key (wif)[Enter to quit]: appears: Enter your private Active Key and confirm with Enter.
1.3. Now Passphrase: appears: Enter any password twice. This is the password of the newly created local "Wallet".
Now you have successfully imported your Active-Key into the local wallet and created a password for the wallet.
This message appears:
==============================
Would you like to make maxpatternman a default user?
You can set it with with:
steempy set default_account <account>
==============================
That sounds great, so let's just do it.
2.1. steempy set default_account maxpatternman Enter your account name here.
3.1. ) With steempy permissions you get the following output:
Your public keys are displayed here.
Please note down your current posting key so that we can keep it apart later.
4.1. Now type steempy allow.
4.2. Now Password for Key Derivation: appears. Enter the password for the new posting key twice.
4.3. Then you will see Passphrase: Here you enter the password from the step 1.3.
Now you will get a relatively long text back, but this should not interest us any further.
If you did everything right, you should see a new posting key with steempy permissions.
Even in your "Wallet" at "permissions" directly on Steemit you can now see both keys.
Now you have the possibility to log in with both keys.
If you want to delete the posting key again, do it this way:
5.1. steempy disallow STM6kRdw3w1xiXWC8ijGkJQZZY1qf61BVSwWr4XYErrzJggH5ob Replace the public posting key you want to delete.
5.2 In Passphrase: type in the password from the local wallet again. (Step 1.3.)
steempy permissions should output the following again:
Thats it.
This is my first Utopian contribution.
Tips, recommendations and corrections are very welcome.