Popular Audio-Technica Dual-Magnet replacement Stylus.
To remove old stylus (needle), hold the cartridge in one hand, grasp the plastic stylus housing with thumb and forefinger, and pull away from the cartridge. The stylus assembly comes away at a slight angle, as indicated by the arrow. 
To install replacement stylus, insert the new stylus assembly into the cartridge at a slight angle, so the hook at the end of the stylus fits into the slot in the cartridge body. The stylus assembly should click into place when fully seated on the cartridge. The stylus must be fully seated on the body for proper operation.

• Although these stylii will fit all the cartridges/turntables/systems listed, some stylus are intended for turntables which have tonearms that are NOT adjustable like the Audio Technica LP60 or Sony LX300.
• Non-adgustable = Use the preset 3g tracking force stylus D1155G or ATN3600L (Round tip) is designed for best operation on novice turntables preset with no adjustments for tracking force or azimuth
• Adjustable = Use the above 3g or the D1155 with a tracking force of 2g. The cross-reference listed turntables, provided they have adjustable tracking force, are generally best suited to the 2g version.