Sitespeed optimization Joomla

Hi freelancers, Please find below the briefing for this optimization. I'd like to improve the site speed of my website: www.ikwilbovenaan.nl. This website is build on Joomla and is a tweaked version of this site: [login to view URL] Currently the speed-scores in Google Analytics are very poor (attachment 1) I have a couple of thing that I'd like to fix (see summary attachment 2) 1- Eliminate render-blocking JavaScript and CSS above-the-fold content (see attachment 3) The page has 20 blocking script resources and 21 blocking CSS resources. This causes a delay in rendering the page. 2- Leverage browsing caching (see attachment 4) Setting an expiry date or a maximum age in the HTTP headers for static resources instructs the browser to load previously downloaded resources from local disk rather than over the network. 3- Enable compression (see attachment 5) Compressing resources with gzip or deflate can reduce the number of bytes sent over the network. I consider success for this project, when the score is over 75 / 100. That is when I will release the full payment. Please outline in your reply / bid HOW you are going to tackle this. Also, AT ALL COST, nothing can happen to the current design and functionality both desktop and mobile. So whenever you would minify a script or compress an image, this should't harm the website in any field. Finally, the site needs to stay live as well at any time. Looking forward to your replies. I will choose the freelancer tomorrow morning CET. Leon