The Lenz LE1025 decoder is a great decoder that has one of the best BEMF control on the market. Tony's Train Xchange does have a great article that compares this decoder with other BEMF decoders.

The following pictures shows a way of installing a LE1025 in the Roco El16

Remove the shell, by widening the body a little bit. The printed circuit board is clearly visible. The Lenz decoder is shown in the location it will be installed eventually. Currently this space is occupied by a switch that allows to change the power pickup from track to overhead wire.

The resistors, capacitor and diodes need to be removed. This picture shows the printed circuit board after the removal of these components. Compare with the previous picture for their location. The capacitor sits underneath the board between the copper strips that attach to the motor.

The printed circuit board is removed and with a small saw the left part that holds the switch is removed.

The switch is gone and in its place sits a piece of white double sided tape. The wires from the bogies are attached again. This requires scrapping off a little bit of isolation of the circuit board.

The decoder is put into place and the red and black decoder wires are soldered to the track pickup locations on the circuit board. The orange and grey wires are soldered to the motor pickup locations, where the capacitor used to sit.

After this is done put the locomotive on the track and select number '3'. If everything is alright the locomotive should run. Please note the direction, because we need this for connecting the function wires.
If the locomotive doesn't run check the wiring again and compare it with the next picture which has a more closeup view of the decoder, printed circuit board and the wires.

The white wire is for the front lights and connect it to the light that is 'front'. The yellow wire goes to the rear. In this example the blue common wire is not used because the lights are connected to one of the pickup wires on the print circuit board. In this configuarion the lights will get half the voltage they used to get. If you prefer to use the blue wire then you have to isolate both lights from the pickup wire on the printed circuit board.

A piece of electrical tape is used to secure the wires and the decoder and the shell/body can be put back on the frame. Make sure that 'cab 1' is sitting in the front location.

The last step is to the program track to program a new address. I use four digit addressing and normally use the last four digits from a Norwegian locomotive number for the address. So in this case the El16.2212 will get address 2212.