Complex sentence: The conversion was achieved by installing vertical launching systems (VLS) in a "multiple all-up-round canister" (MAC) configuration in 22 of the 24 missile tubes, replacing one Trident missile with 7 smaller Tomahawk cruise missiles.
Split into simpler sentences: The conversion was achieved by installing vertical launching systems (VLS) in a "multiple all-up-round canister" (MAC) configuration. This system was installed in 22 of the 24 missile tubes, replacing one large nuclear strategic ballistic missile with 7 smaller Tomahawk cruise missiles.