Interconnect, and solder. Ideally, the leads should not form a kink, but be in a straight line. Sometimes, if there is existing spagetti tubing, I'll slip the new part' s lead into the tubing alongside the old part's stub of a lead, and at a point where both leads show outside the spagetti, solder them together. The new cap should roughly occupy the same location the old part was in, especially in high frequency RF areas of the radio. Be sure to use the same connection points for the new replacement parts, even if one is the ground.
Ground loops causing hum can result if another ground point is used.
The manufacturer selected suitable points to ground things, and to use other points can cause hard to find problems. To repeat, do not remove all the caps and then install new ones. You risk forgetting where what went. Better to remove one cap, and install its replacement, one at a time. Older transistor radios can have capacitor trouble.