=== Initialize git repository ===
<code bash>
$ git init
</code>

=== Connect to remote repository (bitbucket) ===
<code bash>
$ git remote add origin git@bitbucket.org:<user>/<repository>
</code>

=== Connect to remote repository (gitlab) ===
<code bash>
$ git remote add origin git@gitlab.com:<user>/<repository>
</code>

=== First push to remote repository ===
<code bash>
 git push -u origin master
</code>

=== Change remote url (gitlab) ===
<code bash>
git remote set-url origin git@gitlab.com:<user>/<repository>
</code>

=== Config alias ===
<code bash>
 $ git config --global alias.hist "log --oneline --graph --decorate --all "
 $ git config --global alias.hisn "log --oneline --graph --decorate --name-only --all "
</code>

=== Git Config Options ===
<code bash>
 $ git config --global user.name "John Doe"
 $ git config --global user.email johndoe@example.com
 $ git config --global core.editor nano
 $ git config --global pager.log false
</code>

=== Pager only for long output ===
To only use pager for output longer than one page

<code bash>
 $ git config --global --replace-all core.pager "less -F"
</code>

=== Add git sub module ==

<code bash>
git submodule add git@bitbucket.org:user/<package>.git <destination>
</code>

=== update sub module only ===

<code bash>
git submodule update --remote <path to the submodule>
</code>

=== Clear git repository on Bitbucket ===
Source: https://stackoverflow.com/questions/13669410/clear-git-repository-on-bitbucket

No need to delete it.

From your new local repo create directory or remote simple the .git, if you want upload (without history) an existing repo:
<code bash>
 $ rm -rf .git
</code>
Recreate the repos from the current content only

<code bash>
 $ git init
 $ git add .
 $ git commit -m "Initial commit"
</code>

Then simply push to the github remote repos ensuring you overwrite history:

<code>
 $ git push --force -u origin master
</code>

That will replace the history of your BitBucket master branch by the new one you have done locally.

Now, if you had pushed other branches before, you might want to delete them.

<code>
 $ git push origin :oldBranch
</code>