Blockquote Auto Number

Here how you can get blockquote with auto number. As always, go to Blogger › Layout › Edit HTML › (don't forget to) backup your template. And then, search for .post blockquote { or .post blockquote { and delete all its occurrences.
It is OK if you couldn't find such code just procedd to the next step. Now search for ]]></b:skin> and just above ]]></b:skin> , paste the code below,

    blockquote {
    background: #fff url(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhepFFTlSsFH8AAy3eJRjSLSnkrKP-QcotZ8mMKBsM_aBoHXSGvXunb6gPWkeEH_0BoSSUjmuaUhkHOoiX_HfoXlHnmdaOp5tdjRjDCiyju5THM1J3lzzTaxh_-17lVOA16VT1APy5CjOk/s320/bloggertipstrickstoolsnseo.blogspot.com-notebook-no.png) repeat-y;
    margin: 0 20px;
    padding: 0px 20px 5px 55px;
    color:#7a7a7a;
    font: bold 0.9em  "Comic Sans MS", verdana;
    line-height: 153%;
    }
    blockquote p {
    margin: 0;
    }

Off course you can customize it by changing the number list background by replacing the bolded image link in the code above with the image URLs of yours.