[Least possibility of getting lost]
Take the Limosine bus to Osaka (Itami) Airport (~75 min), and change to the Osaka Monorail.

[Alternative-1]
Get off at JR Osaka Station, take the Subway Midosuji Line bound for Senri-Chuo Station, and change to the Osaka Monorail.

[Alternative-2]
Get off at Namba Station on the Nankai Line, take the Subway Midosuji Line, get off Senri-Chuo Station, and change to the Osaka Monorail. (time required: about two hours)