changing remington 700 barrels question

[scooterman27006]

i have a fairly new 204 caliber adl 700 remington and it just wont shoot - another story there - anyhow i bought a 222 remington barrel -it hasnt come yet and its used - anyhow i want to put the 222 barrel on the adl and take the 204 barrel off -- whats involved here - will it work and will i have to have a gunsmith to do a lot of expensive work before i can shoot it - the stock and action have had some work done on them trying to get the 204 to shoot but no luck and this 222 barrel is slightly used - can i use the same bolt and should this work out ok and should it shoot ok after the change or did i waste money on a barrel - got it for about 50 bucks so i am not out of a lot thanks scoot and any suggestions here is appreciated