I’ve edited this slightly to save some confusion 
You have to remove the rubber trim by compressing the little white tabs underneath the metal lip below.
Pull off the rubber caps on the wiper arms and remove the nuts x2. Note the position of the wipers for refitting. Lift the wiper arms up and push the short section at the end with the nut down and away from the nut and remove from the stalks.
Now trace down and disconnect the single washer jet hose from its union inside the drivers inner wing next to the brake master cylinder
Close the bonnet on its catch and remove the small plastic covers at both ends of the scuttle with a thin trim tool or flathead screwdriver to access the 10mm screws, being careful not to scratch the actual scuttle.
Once these are out you can raise the bonnet back up and pull the scuttle panel forward and it will fold slightly in the middle and lift off. You will probably need a new set of screw covers and grommets which mx5 parts sell for less than 10 pounds. Refitting is the reverse of removal .
When it comes to removing the grommets I find lifting one of the short edges up and using some pliers to tug on it until it pops out. This may slightly deform the metal around the hole as its very pliable. You’ll need to flatten this back down as best you can before fitting the new grommets, I did mine as per this pic and then used waterproof tape over the top tucked in under the lip of the windscreen.
