WORDPRESS modifying php.ini and .htaccess for localhost with MAMP

I'm having a heck of a time configuring my MAMP localhost to fit the recommended server settings for the Wordpress theme I'm using. I'm using MAMP, not MAMP Pro. I need to increase the values to at least this:

Snippet for php.ini

memory_limit = 256M 
post_max_size = 128M 
upload_max_filesize = 32M  
max_input_vars = 3000
max_execution_time = 300​

Snippet for .htaccess

  php_value memory_limit 256M
  php_value post_max_size 128M
  php_value upload_max_filesize 32M
  php_value max_input_vars 3000
  php_value max_execution_time 300​ 

I was able to resolve memory_limit, post_max_size, and upload_max_filesize. Here's how I did it (in case I need to do it again and forget what I did):

• With MAMP server running, I opened the WebStart page, then went to Tools > phpMyAdmin
• Under Web Server, I found out which PHP version it's using (this is important because my MAMP\conf directory had almost three dozen versions and I didn't know in which version to alter the php.ini file)
• I went to the noted MAMP\conf directory and Ctrl+F for "memory_limit" "post_max_size" etc and changed the values
• I saved the file, stopped and restarted my MAMP servers, refreshed my Wordpress Status page
• I saw that the values I changed were no longer red (in warning), so success

How do I update max_input_vars and max_execution_time? Do I just stick both of those in there somewhere?

Where/which is the correct .htaccess file?

Please halps! Thanks so much!

ADDENDUM: I found my .htaccess file in the root folder of my Wordpress site. I have no idea what to do from here. Do I just paste in everything in the block? It looks like this:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /localwpLLM.dev/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /localwpLLM.dev/index.php [L]
</IfModule>

# END WordPress