WARNING: This page is about a different car, the 2012 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
Using the special tools, MD998812, MD998813 and MD998822, indicated below, install the 5th speed gear sleeve.
Fig 1: Installing 5th Speed Gear Sleeve Using Special Tools, MD998812, MD998813 & MD998822