How do I unlock rank 4 parts for the Gundam F91?

Unlock and clear the "C'mon, c'mon! Bring it on!" Extra Mission.

To unlock the mission, you must max out your relationships with Seabook and Cecily, as well as complete all three anti-Cosmo Babylon Friendship Missions and read the terminal message you receive afterwards. More.

Unlock and clear the "White Devil" Extra Mission. To unlock the mission, you must max out your relationship with Amuro and Bright, as well as receive and read the terminal message sent for completing all three Earth Federation Friendship Missions. More.

Unlock and clear the "Zero vs. Epyon" Extra Mission. To unlock the mission, you must first receive the "Sanc Kingdom" terminal message from Relena (which is sent as soon as you max out your relationship with her). You cannot get this message while playing as either Heero or Milliardo, so you must use another character.

To play "Zero vs. Epyon", you also must shoot down 3000 or more enemy units while playing as Milliardo. Note that "Zero vs. Epyon" is playable for Milliardo only, is restricted to one-player only, and requires that you pilot the Wing Gundam Zero. More.

Clear the first two missions of Kamille Bidan's Official Mode (Re-entry to Earth and Winds of Jaburo) on any difficulty and keep all allied pilots alive in both missions. The key to meeting this requirement is to rescue Emma Sheen ASAP during Re-entry to Earth -- she will retreat if her MS takes any appreciable damage, and that will torpedo your efforts (as she will count as an ally not saved for this mission and won't even appear in Winds of Jaburo). More.

Unlock and clear the "Look! The East burns Crimson Red!" Extra Mission.

To unlock the mission, you must first clear the "Behind the Scenes" Friendship Mission and read the terminal message received immediately afterwards. "Behind the Scenes" is unlocked when you read a terminal message received if your character has cleared 20 or more missions and you've cleared all three "Gundam Fight" Friendship Missions with that character. To play the "Look!

The East burns Crimson Red!" Extra Mission, you must also shoot down 3000 or more enemy units while piloting the Master Gundam (combined total for all pilots). More.

Unlock and clear the "You're in my way!" Extra Mission. To unlock the mission, you must possess a license for the Gundam Mk-II series and have completely assembled the Byalant, Baund Doc, and Marasai.

You must also max out your relationship with Jerid Messa (or, if you're playing as Jerid, attain a pilot level of 30 or higher). Note that you're restricted to piloting mobile suits not used by Jerid in this mission. More.

Unlock and clear the "Persevering Justice" Extra Mission. To unlock the mission, you must max out your relationship with Athrun, clear the "The Great Escape" Friendship Mission (which is unlocked when you agree to help Athrun leave ZAFT while doing the ZAFT Friendship Missions), and shoot down 3000 or more enemy units while piloting the Infinite Justice Gundam (combined total for all pilots). More.

Unlock and clear the "Burn, Dragon" Extra Mission. To unlock the mission, you must clear Glemy Toto's Story Mode and shoot down 3000 or more enemies while playing as Glemy. This mission is playable for Glemy only, and it requires that you pilot the Bawoo.

More.

Unlock and clear the commemorative "40,000 Total Shot Down Enemies" (which counts totals for all pilots) Free Mission and read the terminal message received immediately afterwards. More.

Unlock and clear the "Don Quixote" Extra Mission and read the terminal message received immediately afterwards. To unlock the mission, you must max out your relationship with M'Quve, clear M'Quve's Story Mode missions without ever getting a Game Over (i.e. Don't save the game if you die during any of the Story Missions), and shoot down 3000 or more enemy units while playing as M'Quve.

More.

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