Editing Author Bio - Gravatar Size & Allowing HTML

Hi there! I’ve been trying to edit the author info box that appears underneath blog posts, and I’m having a bit of trouble.

First, I would like to enable HTML so that I can add links & text formatting. People suggested adding the following piece of code:

remove_filter('pre_user_description', 'wp_filter_kses');

In the themes functions.php file (I’ve made a child theme, so I’ve put it in the functions file there). This didn’t work, and the HTML I’ve added isn’t recognised - http://scratchmapproject.com/a-day-in-cambridge/ (scroll to the author box, I added a few test tags in there).

Also, I wanted to make the avatar bigger. The default is 90px, and I read that the best way to do this is by applying a filter.

apply_filters( 'get_avatar', string $avatar, mixed $id_or_email, 150 $size, string $default, string $alt, array $args );

Would I also put this in the child theme functions.php file, or does this go somewhere else? Does the filter work on its own, or do I need to write a helper function to go with it? All I’m trying to do, is change the size to 150px, instead of the default 90.

Many thanks in advance!