BP Template Pack Flexx Professional theme

My website is https://www.theifhl.com and I have always used (currently using) the Flexx Professional wordpress theme. I added Buddypress to the site and now some pages are not displaying properly such as this one – https://theifhl.com/members/

Can I fix that? I tried to use a new theme but it was too much work to change the new theme so I want to just keep this current theme.

I just found the Buddypress Template Pack – https://codex.buddypress.org/legacy/wordpress-to-buddypress-theme/#template-packed-wordpress-themes
I added the plugin and got stuck on Step 3… I don’t understand how to make the template changes (probably because I’m a noob).

Note: My flexx wordpress theme is a 3-column theme and I don’t think it’s a child theme

Again here’s the site – https://www.theifhl.com
And here’s one of the pages not displaying correctly – https://theifhl.com/members/

How do you fix that?