1. Megaton
Go up to the Water Prosesing Plant (sorry about the spelling) and turn around, you will see the back of Lucas Simms house. Look up and you will see an entrance on the roof. Get something to jump on and climb up. Then there will be a stairwell that leads up to the top. Lanch the nuke here.

2. Tennpenny Tower
Get in to Tennpenny, then go up the elevator across the lobby from the entrance. Then turn left and there will be a door. Open it and go to the big double doors. You will be on a balcony, shoot the bomb here.

3. Rivet City
This one is simple. Go to Rivet City and at the end of the dock shoot the nuke here.

4. The Highways
Any highways you can get on.

5.WKLM Radio Station
Theres a cliff behind the Station

When at a enclave post and there is a deathclaw in a cage, kill the enclave without beeing spoted and take there plasma mines then put them in front of the door and open the cage when it runs at you it goes BOOOOMMMMMMM!!!!!!

Use your local map to find hidden doors

You CAN fix your T-51b and medical armour. If you take all the power armour you have out of your locker( or wherever you put them) you can fix m with normal or outcast armour. This only works if you have every kind of power armour in your inventory.

If you try and clock the game straight off and end up with your last objective which is to turn on the purifier then let me tell whatever the choice you make you end up with the same ending.

When you are heading to the Galaxy New Radio station in D.C. Enter from the north, it's faster. When you are near the radio station, you will see the Brotherhood of Steel take out some mutants. Help them fight there way throw to the radio station. After the battle is over, you will see some of the the brotherhood members got killed, but only one of them has a fat-man.(the fat-man shoots mini-nukes)

Go to Minefield. North-west from there is the MDPL-13 Power Station, go there and dew north of there is the crashed alien space-craft. There you will see the dead alien pilot, a alien ray gun, and 120 ray gun ammo. You will know when you are near the alien space-craft when you start picking up alien distress signals and you get minor radiation.(note: the ammo for the alien ray gun is not available anywhere else so unless you can got to different planet in a different galaxy, use it with smartness, and the space-craft is minor radiated.)

When hacking a terminal there are groups of symbols highlighted by these: [] or {}. These groups of symbols will either be dud passwords or reset the number of tries you have to guess the password but not reset the password itself. Also after your third fail you can just exit the terminal and retry but this does reset the password. Or you could just save before hacking then when you fail just reload. Also I have found more often than not that the password on the “very easy” terminals is the first word on the left column. I don’t know if it’s the same for “easy” terminals but feel free to try, just don’t blame me if it’s wrong. I haven’t failed a hacking yet thanks to these methods.

Also for lockpicking, when the bobby pin is close to breaking you can just exit and retry the “minigame” and the bobby pin should be in perfect condition. Or you can, as before, just save prior to picking the lock then if you fail you can just reload; I have saved lots of bobby pins using these methods.

Go to rivet city and talk to doctor li in the science lab to complete the quest
If you do not know where rivet city is talk to lucas simms in megaton and you will get a map marker.