MLG HAS RWY CHANGE JUST AS TURNING FINAL; OVERSHOOTS LOC. TCASII RA ALERT.

Narrative

WE WERE 10000 FT AND DSNDING ON R DOWNWIND AT LAX ABEAM THE ARPT; ALL RWYS IN SIGHT. I ACCEPTED A STADIUM VISUAL APCH. SKIES WERE CLR OF ANY CLOUDS. TURNING BASE AND NEARING FINAL WE COULD BARELY MAKE OUT 1 PAIR OF PARALLEL RWYS BELONGING TO LAX. WE WERE CLRED FOR VISUAL TO 24R AT FIRST; BUT WERE ASSIGNED 24L JUST AS I WAS TURNING A DOGLEG TO FINAL. WHILE WE WERE SWITCHING LOC FREQS; ETC; I VISUALLY PROCEEDED TOWARD THE RWYS ON THE DOGLEG HDG. THE 2 RWYS WE HAD SEEN FIRST TURNED OUT TO BE THE LAX S COMPLEX; RWY 25L AND 25R. AS WE WERE ABOUT 1500 FT RIGHT OF THE RWY 25R FINAL; ABOUT 5 OR 6 MI OUT 3 THINGS OCCURRED SIMULTANEOUSLY: ATC CALLED INSTRUCTING ME TO CORRECT BACK TO THE R AS I WAS L OF THE 24L COURSE. TCASII WENT OFF 'CLB; CLB;' AND I NOTICED TFC ON THE SCOPE SLIGHTLY TO MY L AND ABOUT 1 MI BEHIND; ROUGHLY THE SAME ALT. THE N COMPLEX (RWY 24L; RWY 24R) CAME INTO VIEW. THE TCASII SWITCHED TO 'CLR OF CONFLICT' ALMOST IMMEDIATELY AFTER THE ORIGINAL 'CLB' COMMAND. I CORRECTED R; AND WE LANDED WITHOUT FURTHER INCIDENT ON 24L. CONCLUSION. FLYING INTO LAX REQUIRES MORE THAN THE AVERAGE PREPARATION AND PLANNING; EVEN ON A DAY THAT AT APPEARS VFR PLUS AT FIRST.