The wired SMD LEDs are designed to run off of 3VDC, so you can easily power them from a 3V coin cell battery.

The holder with switch make it simple to get started (and to test LEDs for color).

The blue wires connect to either GND pad, and the red wires connect to the Sw pad if you want to use the on/off switch. The On pad is always on regardless of switch position.

Semi-Permanent Solderless Wiring

While soldering would be ideal, you can get by pretty well by twisting together all of the blue wires to each other and all of the red wires to each other of multiple LEDs and then twisting these bundles in the coin cell breakout pads as shown here.

This is a parallel circuit, in which each LED draws the full power, so there's no need to worry about dimming as in a series circuit.